Chelsea manager Liam Rosenior has revealed his squad have been hit with a virus that has affected players and staff. The Blues were without Liam Delap and Jamie Gittens due to illness for their Carabao Cup semi-final clash against Arsenal and both players have been ordered to stay at home. More staff members have also been affected ahead of Saturday's Premier League clash with Brentford.The Blues are continuing to battle a bug that has ripped through the Chelsea squad in west London. Gittens and Delap remain sidelined due to illness and have been ordered to stay at home, while more staff members have also been affected, according to The Athletic. The situation comes just days after Rosenior replaced Enzo Maresca at the helm and amid a hectic run of fixtures for Chelsea and their new manager. The Blues are due back in action on Saturday against Brentford in the Premier League and still have games against Pafos, Crystal Palace, Napoli and West Ham to come before the end of January.Rosenior spoke about the situation at a press conference on Thursday. He said Delap would not be back in time for Saturday's game and delivered the latest on the situation. "No, he’s still at home at the moment, recovering. As is Jamie Gittens. Our club doctors are doing everything they can to contain what looks to be a virus because some members of our staff have come down with it as well. We had a meeting today with the players about washing your hands, the basics, which is really important and hopefully we can contain it. We have a busy period, so we need everyone ready to go and fit and healthy.”Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!Rosenior did have better news on Romeo Lavia who has endured a nightmare time with injuries at Chelsea. The midfielder was ruled out of action again in November but is closing in on a return to training. Rosenior said: "Romeo is on the pitch, he’s not with the group yet but we can see him out on the grass doing his rehab. He is looking really, really good. I love him, firstly as a lad but also as a player. He's someone I would love to work with in the long term because he's just an outstanding footballer. The most important thing for him now is to make sure we don't push him too hard, so that when he does come back, he's back for good and I can get some real work into him tactically. For me, he's a player I can't wait to have back in the group, and I'm really, really looking forward to having him back with us."Add GOAL.com as a preferred source on Google to see more of our reportingRosenior faces an in-form Brentford next as he takes charge of Chelsea for the first time in the Premier League on Saturday. The Blues possess a disappointing record against Saturday's visitors and have won just one of their last eight Premier League games against the Bees. Their home record has also been a concern in the 2025-26 campaign, something Rosenior is keen to change. He explained: "I think the past is the past, I said that to the players. I can only affect the now. If I affect the now, I affect the future. I want us to play with high tempo so the opposition know it is difficult to come and play at Stamford Bridge. The most important thing is that we do the basics really well."Brentford will make the short trip to Stamford Bridge two points and three places above Chelsea in the Premier League table. Keith Andrew's side are on a run of six games without a defeat, with the two sides having played out a 2-2 draw earlier in the season at the Gtech Community Stadium.