The young full-back started on the bench at Charlton on Saturday but an early injury handed him a chance and he impressed in a 70-minute stint as the Lions won 2-0 at The Valley.
That was Adam's 25th appearance in all competitions for Millwall so far this season, including three in a fantastic FA Cup run that has taken the Championship side to the semi-finals at Wembley.
Millwall overcame Blackburn in a quarter-final replay at Ewood Park last week and will now take on Wigan on Saturday, April 13 for a place in the FA Cup Final.
"It would be a fantastic experience, it's a massive game and hopefully I’ll now keep my place in the team and get to start," said Adam.
"There are a lot games between now and then, so I’ll have to maintain my form.
"You have ups and downs in football, I’ve had a bit of a down being of the starting 11 in the last couple of matches but I got my chance early on Saturday, and now I'm up again.
"It’s a special occasion, a semi-final at Wembley, you don’t need to say any more than that really.
"Everyone thought we had no chance in the replay at Blackburn and we’ll be confident against Wigan as well, suddenly then you are in the FA Cup Final. That’s how big it is."
Adam had an early taste of Wembley - he appeared as a 15-year-old in only the second international to be played at the new national stadium in April, 2007.
He was joined by team-mates Dean Parrett and Andros Townsend in the England Under-16 team in a 1-0 win against Spain.
"That seems quite a few years ago now," said Adam. "I'm sure you can imagine what that was like for a 15-year-old in a stadium like that and playing in front of 30,000 people. It was certainly something special."