The 18-year-old replaced Gastón Ramírez with ten minutes remaining in the cup tie as Southampton looked to wipe out a two-goal deficit late on against the Black Cats. Unfortunately, the game ended 2-1 but it was certainly a night to remember for the youngster.
After being handed an unforgettable opportunity, Gallagher is refusing to rest on his laurels as he pushes for more involvement at senior level.
“It was just amazing,” the forward recalled when speaking to saintsfc.co.uk
. “It’s all sort of a blur, really.
“I wasn’t too nervous in the changing rooms but when I was warming up I got the call from the gaffer to come over – that’s when it really kicked in.
“Because it was away, we didn’t really have many fans. It was when they (Sunderland) were on the ball that the crowd was making all the noise, so it didn’t really have an effect. It didn’t load as much pressure on. I enjoyed it – it was amazing. I just want to be more and more involved.”
Gallagher has enjoyed something of a sudden meteoric rise through the ranks at Saints, with his permanent propelling to the Under-21s side preceding his First Team display.
The Scotsman kept his place in the squad for last Saturday’s 4-1 Premier League victory over Hull City, where he was an unused substitute.
While Gallagher is keen to maintain this progress at Southampton, he is also eager for that to be replicated on the international stages as he strives to play more for Scotland’s young sides.
Reflecting on the experience against Hull, Gallagher added: “That was just another step up with it being at home. It made the experience ten times better.
“U21 training is a lot more intense. The work is a lot harder, which is good. I feel the benefits.”
Sam now heads north of the border for a two-day training camp with the Tartan Army's Under-19s this weekend – something he is looking forward to.
“We’ll go up there (Scotland) and just have two or three training sessions to get the boys the together again,” he said.
“We’ve got some more games coming up soon because we qualified for the Euros (2014 UEFA European Under-19 Championship Elite Round qualifiers), so that’ll be good.
“I’m happy with Scotland. I’d just like to kick on and try to work my way up the age groups there.
“I haven’t really played too many games for Scotland U19s, so hopefully I can now get more involved there and look to make my way up like I have done at the Club.”