Rosenior was broadly pleased with his team despite the defeat – his first since taking charge – and highlighted positives in almost every individual performance.
“The biggest problem for us is that we had a lot of illness, injury and we’re playing against a very, very good team,” added Rosenior.
Cole Palmer, Reece James and Malo Gusto all failed late fitness tests, while Moises Caicedo was suspended and illness forced Liam Delap and Jamie Gittens on the sidelines too.
On Palmer, Rosenior said: “He had a minor strain in his thigh. If you play a player too early in January with a minor strain, it can turn into six weeks out. I can’t afford to lose Cole Palmer for six weeks because he’s that good.”
He added James had “a big knock on his hip”, but “hopefully he will be back for Saturday”.
“Gittens was ill last night, Liam Delap was due to play – he was ill four hours before the game,” said Rosenior.
“Both of them had really high temperatures – dangerously high. Hopefully they can rest up and will be OK for Saturday.”
Rosenior was keen to point out Chelsea had competed well against an Arsenal side that had lost only twice in all competitions this season, and his team can still fight back in the second leg at Emirates Stadium on 3 February.
“We’re playing probably the best pressing team in Europe today, with their full‑strength team, and we’re missing a lot of players,” he added.
“I was proud of the bravery of the players to try to execute certain aspects of what I asked. In six days, we’ve had two games. I’m not asking for time because I think the group are good enough to win now.
“But I need to put my stamp on the team as well – otherwise there’s no point in me being here. So it’s a fine balance, and hopefully the fans will see the progression in the team. But we need to win at the same time.”
