The Jambos host the Reds at Tynecastle in the first leg of their Europa League qualification play-off tonight and McGlynn wants his side, which is littered with players under the age of 23, to put their best foot forward from the outset.
"We don't have loads of options so if I take a young boy out he'd only be replaced with another young boy," he said.
"They've got to grow up quickly and learn from the experience.
"You aren't the finished article at 17 - nobody is - but what a chance this is to play against top quality players, which can only benefit them.
"We must be brave and try to knock Liverpool out of their stride.
"We will not be able to match them in every area of the pitch physically because we don't have that.
"But we do have flair players who are probably lighter and thinner but maybe have pace and skill.
"We'll have to see if that will be enough."