Maurizio Sarri says Chelsea “are in trouble” after Olivier Giroud became the latest Blues player to suffer an injury.The France international limped off during the second half of Sunday’s 1-0 win against Crystal Palace and had to be replaced by Alvaro Morata.Sarri confirmed after the game that Giroud had picked up an ankle problem but doesn’t yet know how long the striker will be out for. Article continues below Editors’ Picks ‘There is no creativity’ – Can Solskjaer get Man Utd scoring freely again? ‘Everyone legged it on to the pitch!’ – How Foden went from Man City superfan to future superstar Emery out of jail – for now – as brilliant Pepe papers over Arsenal’s cracks What is Manchester United’s ownership situation and how would Kevin Glazer’s sale of shares affect the club? “The problem is his ankle. I don’t know the severity,” said Sarri. “We have to wait for tomorrow. I think that, later in the evening, I will see the doctor for the first results, but I think the real result will only be known tomorrow.”Sarri was already without a number of players for the game at Selhurst Park, including Pedro, who suffered a hamstring injury against Watford on Boxing Day and will be sidelined for two weeks.Cesc Fabregas, Danny Drinkwater, Ruben Loftus-Cheek and Callum Hudson-Odoi were also missing for the trip to south London, leaving Chelsea short on numbers at a critical time of the season.After playing nine games in December Chelsea face a further seven games next month, with a two-legged Carabao Cup semi-final against Tottenham and FA Cup third round tie with Nottingham Forest adding to their workload in the Premier League.That number will rise to eight should they overcome Forest and reach the FA Cup fourth round, scheduled for the final weekend of January.That has left Sarri concerned about how his side will be able to manage such a heavy workload.He added: “In the last few days we were a bit unlucky. Yesterday in 10 minutes we had three injuries – Fabregas, Loftus and Drinkwater – then Giroud today, and we were already without Pedro and Odoi.“We are in trouble because, in January, we have to play every three days.“Fabregas is a neck problem. The injury was in the last five minutes of training, so I’m not sure whether he has to rest for two or 10 days. I will have a meeting with the doctor this evening.”N’Golo Kante scored the only goal at Selhurst Palace to move Chelsea five points clear in fourth place.Next up for the Blues is a home game against Southampton on Wednesday.