Chelsea chief Michael Emenalo admits their loan players this season have been a bit "hit and miss".
Emenalo, however, says they're delighted with the form of Tomas Kalas in Holland.
"Gael Kakuta is getting rave reviews about his training at Bolton but is having difficulty breaking into the team, but has been terrific when he has played. Patrick van Aanholt started very well at Wigan but eventually lost his place when they had some poor results and the manager, Roberto Martinez, wanted to revert to what he had had before, so we have told him to work hard and stick with it.
"It's always a bit hit and miss but more hit than miss, and we are happy with where we are."