The lads are back in FA Premier Reserve League action against Derby County at Stevenage Borough FC tonight (7pm) with only Lars Hirschfeld and Jonathan Blondel featuring as regulars from the first team squad.
But boss Colin insists the experience a lot of the youngsters gained from playing reserve team football last season should now stand them in good stead.
Colin explained: "A lot of the lads who have played this year came in last season and had good experience of reserve team football.
"So much so, even though they are young, I expect of them now.
"The demands are there and albeit they're still young, they've had experience and the question we put to them now is with that experience, what have they learned?
"We should see an improvement and the mistakes from last season should be limited to last season. We'll put that quite forcibly to them.
"The lads have to grab their chance either to cement their place in the reserve side next time out or to say to the manager that perhaps they deserve to train with the first team group. It's up to them to take that chance."
Derby have always been a force at reserve team level and despite only losing six games, were pipped into third last season by Arsenal on goal difference. Ipswich Town won the title by six points.
Colin added: "There are a few boys who played against us last season who have now played in the first team. They'll either have the same type of side or more experience.
"The things Derby have always had over years, speaking as a manager and having played against them, is organisation, discipline and they always have a go.
"They've never let themselves down whenever I've seen them.
"They are always up there in the league and that's a good indication that their attitude is always right when they play.
"It will be tough but we're all looking forward to it."
Squad: Hirschfeld, Henry, S Kelly, O'Donoghue, Snee, Galbraith, Ricketts, Bortolozzo, Blondel, Barnard, Sutton, Hughes, Slabber, Dobson, Marney, Jalal.
Colin Calderwood says expectations have now been raised for his young reserve group.