Cole Palmer is not in the Chelsea squad on Sunday as they travel across London to take on Crystal Palace in the Premier League.
The England international has been dealing with a minor thigh problem and missed the Champions League win over Pafos in midweek.
Blues boss Rosenior said on Wednesday night that Palmer was rested against the Cypriot side but was likely to be available this weekend against the Eagles.
However, the 23-year-old is not involved in the London derby due to the thigh issue persisting.
Rosenior explained the situation ahead of the contest at Selhurst Park, hopeful that Palmer will be available on Wednesday when Chelsea go to Napoli in the Champions League.
‘Unfortunately for us Cole’s not quite right for this one,’ the Chelsea manager told Sky Sports.
‘I’ve said before in press conferences we want to make sure that every player is 100 per cent. There’s no use risking players in January for what we want to achieve.
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‘He’s got a little niggle in his thigh, he’s not quite 100 per cent, but he’s got a chance for Wednesday, hopefully he’s back for then.’
The former Manchester City playmaker has had a frustrating season so far, making just 12 Premier League appearances due to injury concerns.
A groin issue has been the chief problem for Palmer, but now he is suffering with a thigh issue and he will have to wait to add to his four league goals so far this campaign.
In Palmer’s absence Rosenior has picked Estevao, Enzo Fernandez and Pedro Neto behind Joao Pedro up top, with Andrey Santos and Moises Caicedo at the base of midfield.
Robert Sanchez is in goal behind a back four of Reece James, Trevoh Chalobah, Benoit Badiashile and Marc Cucurella.
There have been reports emerging this month that Palmer is homesick for Manchester, where he grew up, and has been linked with a move to Manchester United as a result.
Rosenior addressed the speculation ahead of the weekend’s action and was confident that Palmer is happy at Chelsea.
‘I’ve had numerous conversations with Cole and he seems, and is, very, very happy to be here,’ said the manager.
‘He is a huge part of our long‑term plans, he’s an outstanding player. Every player goes through difficult moments in their career with injuries, but that is no indication of his quality.’
