Liverpool were denied an early penalty after Daniel Sturridge was brought down in the area but the referee failed to award a spot-kick.
The visitors made the breakthrough shortly after when Lucas Leiva glanced a header past Plymouth goalkeeper Luke McCormick.
The away side were awarded a late penalty after Alberto Moreno was brought down in the 86th minute but Divock Origi missed his spot-kick effort.
“You’ve got to give them a chance to see whether they are capable and they can survive at this level,” Gerrard told BT Sport.
“The kids are all lucky because they’ve got a manager who believes in them. He’s given them all a chance. Over the two games, there wasn’t much quality.
“Philippe Coutinho put a good cross in and Lucas scored a good goal. Over both 90 minutes, it wasn’t a great tie.”
The Reds will host Wolverhampton Wanderers in the FA Cup fourth round at Anfield on Saturday 28 January.
Liverpool are in third place in the Premier League table and seven points adrift of leaders Chelsea.
The Merseyside outfit will make a return to Premier League action when Liverpool host Swansea City on Saturday afternoon.