First, the good news. I know, I know, you're supposed to lead with the bad news. But that's a bit more complicated, so we'll save it for after the less complicated bit, which is that Victor Moses is "fine." Whatever it was that caused him to limp off the pitch against Fiorentina — was he rubbing his eyes? was he favoring a leg? was he holding his head? — is apparently nothing serious and he should be ready for the start of the season on Saturday.
Diego Costa, on the other hand, may not be ready for the start of the season. When might he be ready? Who knows.
I have to be honest and say that it is a bit of a concern. A player that didn’t finish the season and doesn’t start the season obviously doesn’t make me happy."
"It was a surprise for me he did not play on the weekend. I don’t risk my reputation again. Before the last weekend I told you he’s ready to play. He wasn’t. I don’t know. I don’t risk to say yes but I also don’t risk to say no."
"The boy is trying hard but he has a problem against Barcelona, the next day the scans show there is no injury so the next day he trains but the next day he is not comfortable and 24 hours before the game we don’t know if he plays or doesn’t play. It is not a good feeling for him, it is not a good feeling for me."
-Jose Mourinho; source: Mail
The first couple times we ran across such situations with Diego Costa, he turned out to be just fine. He even tended to score goals by the handful, so the joke eventually became that a mystery injury diagnosis basically meant that Costa will score a hat-trick on the coming weekend.
But as last season wore on, that joke got worn out, mostly because Costa ended up getting truly injured over and over and over again. Hamstring injuries, by definition, are annoying and tough to properly treat and to let heal, but Costa's seem particularly bad. At the end of last season, we opted to not have him go under the knife to try to fix things once and for all, and the way things are looking right now, despite Mourinho's confidence in Falcao and Rémy, that decision might prove pretty silly.
Unless Costa hits Swansea for another hat-trick.