Jose Mourinho said some of his Chelsea players did not impress enough in the 2-1 League Cup win at Shrewsbury to keep their place in the side.
The Blues struggled against their League Two opponents on Tuesday, and needed a late own goal to secure their berth in the quarter-finals.
"I expect people that have not been playing a lot to raise their level and create problems," said the manager.
"I love problems of choice, but it's easy to choose my team for Saturday."
Dane Andreas Christensen, 18, was given his debut, while fellow defenders Nathan Ake, 19, and Kurt Zouma, 20, were also given starts.
Egypt winger Mohamed Salah, an £11m signing last January, was replaced by Willian, who provided the assist for Chelsea's winner.
Mourinho, however, did praise goalscorer Didier Drogba, midfielder Oscar and defenders Gary Cahill and Filipe Luis for playing two days after helping Chelsea to a 1-1 draw at Manchester United.
He added: "I also had people like [goalkeeper] Petr Cech and [midfielder Jon Obi] Mikel, people with lots of years at the club, who would prefer to start at Old Trafford.
"They didn't and they came here today and gave a fantastic example. After that there are the young boys and they have to follow the spirit and the professionalism of the others."
The Portuguese boss, who guided Chelsea to success in the Cup twice during his first reign, also paid tribute to 36-year-old striker Drogba.
The Ivorian, also in his second spell with the club, scored the first goal and then contributed to the 81st-minute own goal by putting Shrews defender Jermaine Grandison under pressure.
"I was worried when they equalised [through Andy Mangan] but we go through and Didier played a massive part in that," added Mourinho.
"Hopefully he will be good for the weekend but we will have to see because right now his character is stronger than his body.
"Maybe what he has done today is through his character - not his body.
"That's what makes players special and any of the young players lucky enough to play alongside him, learn from that."