Three Under-21 players featured for McClaren’s men in the 1-0 victory over Charlton Athletic last round, as the head coach made six changes to deal with the intense bout of Championship action.
However, Derby will now be looking to secure their place in the last-16 for the first time the 2008/09 season, when they reached the semi-finals of the tournament - only to be knocked out by Manchester United 4-2 on aggregate.
Having started the Championship season in a slow manner, a good cup run gives Derby a chance to unite as a squad, and McClaren is aware that picking his best squad guarantees the best chance of success.
Speaking to dcfc.com, the former England head coach said: “We want to progress in this cup and we have got players who we need to give games to.
“We go on, have no rest, buts it’s better than training and as long as they keep playing like that, we will be ok.
“I want to win the game, so I will pick the best team that can do that. I will look at the squad, look at the freshness of them, see the little niggles and make sure we put a team out there that can compete and go through.”
Derby struggled to a 2-2 draw with manager-less Cardiff City on Saturday, coming from two-goals down to claim a late draw at home.
The Rams currently sit in eighth place in the Championship, having claimed 13 points from eight games, winning three matches this term. McClaren has overseen victories over Carlisle and Charlton in the previous rounds of the League Cup.