Such is Gallen’s modest character he became flustered and somewhat embarrassed by the Charlton manager’s public praise.
By and large the 45-year-old from Acton likes to stay out of the limelight and let his actions do the talking.
But Gallen is helping to build something special at The Valley, alongside Bowyer, club legend Johnnie Jackson and goalkeeper coach Andy Marshall.
The good times look on course to return for the south London outfit, which is all the more impressive considering the continued uncertainty behind the scenes regarding the ownership of the club.
Under Bowyer’s management they are vying for promotion back to the Championship via the play-offs this season.
They travel to Doncaster on Sunday in the first-leg of their semi-final clash, which is LIVE on talkSPORT 2.
It hasn’t been easy though – far from it. Gallen has confessed to ‘many sleepless nights’ during his two-year tenure as head of recruitment to date, but says the role is one which has really enhanced his skill set.
Speaking exclusively to talkSPORT.com, he said: “My role has been a lot more than the head of recruitment here this year.
“We have no chief executive, so I have taken on a lot of extra responsibilities – drawing up the contracts is just one of those things.
“It’s been a real transition for me, at QPR I was dealing with the academy and then the Under-23s, but at Charlton I am involved in all the departments.
“I feel I’ve gained a lot of experience and as a result have a much better understanding of all aspects of the running of a football club.
“It’s really nice to be somewhere now where I have a position that can make a difference. I’m really enjoying it.
“It’s me, Lee Bowyer, Johnnie Jackson and the Academy Manager basically organising everything, and there’s a really good balance between us all.”
Gallen has taken full advantage of his break in the game – something he wasn’t sure that was ever going to come his way.
When 19 years of loyal and excellent service working at his beloved QPR came to an end back in January 2016, he was unsure where his future would lie.
A short, yet productive spell managing Hong Kong Pegasus followed later that year, but being the family man he is Gallen was always destined to return to the UK.
After returning to the Rs in a part-time capacity as an opposition scout, an opportunity arose for him to join Charlton as head of recruitment in April 2017 – working alongside friend Karl Robinson – and it wasn’t something he was going to pass up.
“It’s been such a whirlwind experience at Charlton, but I’ve loved every minute of it,” he said.
“I’m the happiest I’ve ever been in football. Some may find that strange, as QPR are of course the team I support and always will do.
“I had an amazing time and have many happy memories of working there in the academy and youth teams, winning many trophies and helping aid the development of young players.
“When I became first-team coach there it was a dream come true – but that’s possibly the unhappiest I’ve been in football if I’m completely honest.
“Although I was unbelievably proud to be in that position, I wasn’t really involved with any tactics, team selection, recruitment and so forth. I really wanted to help influence things.
“But when I got to the top at QPR – the pinnacle for me really – I felt like the door had been closed on me in some ways.
“It’s so different at Charlton. I’m involved with a great group and it feels good.”
While Robinson parted company with Charlton last March, Gallen stayed put.
He has now overseen four transfer windows during his stint in south London with the Addicks operating on a comparatively modest budget for a League One club.
When first taking up the role Gallen was told that cutting the wage bill was an immediate priority.
It has been trimmed down 30 per cent during that time – but Charlton still remaining fiercely competitive on the field.
Gallen has played a key role in a number of shrewd acquisitions that have been made in that period, none more so than Lyle Taylor.
“I spent weeks trying to get Lyle Taylor,” he explained. “Every day I was going flat out to get him, it was exhausting and mentally draining.
“It nearly took me a week to recover from that process. I just wanted to sleep and do nothing else – it was one of the most difficult and challenging periods of my life.
“But you look at the impact he’s had at this football club on the field and the way he’s conducted himself off the field, and you think to yourself ‘you know what it was worth it in the end’ – he’s been first class.”
Explaining the process behind the deal, Gallen added: “Jason Pearce [defender] had played with Lyle so he helped persuade him to come here and I also spoke to a couple of Lyle’s former coaches.
“Lee and myself then met up a couple of times with Lyle and his representatives and were thoroughly impressed with the way he came across.
“Sunderland offered him more money, then there were Oxford, Southend, Bristol Rovers – they all wanted him – but the lad decided he wanted to come to Charlton.
“We knew getting him in could be a game changer – the difference between promotion and mid-table obscurity.
“Losing Karlan Grant was obviously very disappointing in January, but it was a good deal for the club, all things considered.
“But last summer was when things were really stressful. Funds were very tight. We knew Lyle would be a crucial signing for this football club.”
Gallen was right. Taylor has established himself as a firm fans favourite, notching 24 goals in 42 appearances for the Addicks – who go into the play-offs as the in-form side in the division.
The recruitment side of things hasn’t been easy for Gallen to operate though, with the ownership of the club still up in the air.
“I was constantly fighting fires – especially last summer,” he sighed.
“Everyone was trying to find a bad story about Charlton and it was making my job a lot harder to get players in.
“We had little money, so we had to work very hard to get deals like Lyle’s over the line. We are only paying a small percentage of Krystian Bielik’s wages for example, too.
“We’re very thankful to Arsenal for letting us have him on loan – he’s been great. At the end of the day a club of this stature deserves success – the fans, the players and the manager.
“I am doing absolutely everything I can in order to play a part in that hopefully occuring.
“If we get promoted it would be unbelievable considering the financial restraints we had to make last summer and in January – on top of everything else going on.”
Gallen has developed a real rapport with Bowyer – readily admitting he isn’t the type of character he envisaged before their first-ever meeting.
“He’s so calm and composed. Hand on heart, I’ve never seen him angry,” he said.
“When he was a player he was a no nonsense midfielder, and I expected a similar character when I first met him – I was wrong.
“We haven’t had an argument, that’s pretty uncommon when it comes to football!”
He added: “Lee is a big pull for this football club.
“I’ve been massively helped in my role by having a guy of Lee’s calibre in the dugout, let’s be honest.
“We’ve attracted some quality players, some much better than League One standard, so he has to take huge credit for where we are right now.
“He’s been brilliant, and I can see him getting to the very highest level in management.
“We have complete faith in one other’s ability and we just bounce off each other really well. Lee’s had a big influence on me.”
Another man who has made a lasting impact on Gallen’s career is none other than Neil Warnock.
The pair worked together for a short period when the veteran boss returned to Loftus Road for a second spell as interim boss back in November 2015.
Gallen says the month he spent alongside the veteran boss was the most rewarding of his career.
“I had one month at QPR when I was working with Neil Warnock and Kevin Blackwell, that was probably the best month of football in my life. I absolutely loved it,” he smiled.
“Before he came to QPR I’d watch him from a distance and I wasn’t sure we’d get on to be honest with you. But then I had the privilege of working with him. He was really, really good.
“Charlie Austin pulled me to one side after the first day of training under Warnock and said ‘I really like him Steve, he’s class.’
“Training was so much fun under him, and everything was so organised and professional. I see similarities between that time and what we’ve got going on here now at Charlton.
“Warnock hammered me a couple of times. I was a 41-year-old man at the time and he made me feel like a 17-year-old – but you know what I still loved him for it!
“I will talk about Neil a lot with Lee Bowyer. When he asks me for advice I’ll say to him ‘this is what Neil would do’ in certain situations.
“Behind the scenes you wouldn’t believe how humble he is. He was so buzzing when he came back to QPR.
“I hope he gets Cardiff promoted again next season – is there any manager better in Championship history?”
Clearly Gallen had a similar impact on Warnock, with the promotion master keen to add him to his coaching staff in south Wales just two summers ago.
He hasn’t been Gallen’s only admirer, as former QPR midfielder Joey Barton was also looking at the prospect of him joining his ranks when he first got the Fleetwood job last summer.
And then there was an offer to link back up with Robinson at Oxford earlier this season – a role where he’d be earning more money than he is at the Valley now.
Gallen turned it down – he has unfinished business at Charlton after all. So what does the future hold for him?
“I thought I’d end up coaching until the day I retired to be honest with you. I kind of fell into this role,” he admitted.
“Whatever I do whether it’s coaching, administration, scouting or the academy – I want to do my best.
“I miss coaching, but I recognise that one day that if i went back into coaching I need someone off the pitch I can trust and go too.
“I think I’m that person at the moment for Lee, doing all the stuff behind the scenes to ensure the club is operating well. It’s like a family here, and I love it.
“I worked at QPR for years and I was no ones man. I wasn’t Neil Warnock’s man, Jimmy Floyd Hasselbaink’s or Les Ferdinand’s. I don’t want to be seen simply as just someone’s man.
“I’m everyone’s man. I’m the club’s man. I don’t do anything that I don’t believe isn’t in the best interests of Charlton Athletic Football Club.
“That’s what kept me at QPR for so long. I didn’t put all my eggs in one basket with one guy.
“I’m excited for the future, I’ve hopefully got another 20 years left in me, who knows what is around the corner.”