Chelsea boss Maurizio Sarri has challenged Danny Drinkwater and Victor Moses to secure their futures by improving their games.
The Italian has admitted he is unsure whether the duo can adapt enough to his system in order to secure long-term futures at the club.
Only Wolves in the Premier League have used fewer players than Chelsea this season, with Sarri sparingly calling upon either Moses or Drinkwater.
Drinkwater has only featured in the Community Shield, while Moses has made just six appearances with only two coming in the Premier League.
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"I don't know; they have to improve, but the characteristics are a little bit different," Sarri said this week when asked whether the duo have futures at Stamford Bridge.
"The situation is that Drinkwater for me is not suitable for a midfield with two midfielders. I told him two months ago what I think.
"And Moses is more suitable for playing like a wing-back than like a winger or a full-back.
"If you look only at the Premier League, the situation is bad, you're right," Sarri added regarding his minimal squad selection.
"But we've used 26 players in all competitions this season. I have to look at all the competitions, because 90 minutes is 90 minutes.
"I think the rotation overall is good at the moment. Of course if you look to December, January, you'll need to change also for the Premier League, because there will be matches every three days."
Chelsea host Crystal Palace on Sunday at Stamford Bridge, live on Sky Sports.