Chelsea has long been expected to address the striker position in the transfer market this offseason and José Mourinho confirmed it this weekend.

Mourinho praised his defense in Chelsea's 1-0 defeat to Crystal Palace while criticizing others for "disappearing."

Chelsea is expected to pursue Diego Costa.

"I don't think it's the moment to speak about next season and the market but it's clear to everybody that Chelsea next year wants to bring a striker," said Mourinho. "What's the future for the other strikers? The ones who are staying are competing with the striker we are bringing [in]. And normally, at the end of the season, players that are not playing a lot or players who are not happy may prefer a change. That is also part of the market. We want to improve the team and the players and make some surgical movements in the transfer window."

Mourinho acknowledged he must also get consistency from Eden Hazard, André Schürrle and Oscar in run-of-the-mill matches, after suggesting the defeat at Palace was an indication of a poor "mentality". "I will try to improve the players," he said. "I can't and I don't need to improve [Branislav] Ivanovic, [Gary] Cahill, John Terry. I can't improve them and I don't need to improve them but there are other guys I need to improve. I think we are doing that step-by-step. But that's not enough to be champions.

"Always, in the back of your mind, you think you might win [the league] but you have to be realistic and you have to analyze the situation and understand. How many points did Chelsea finish in the last two seasons behind the team in first? How many points? [25 and 14] That was for a reason. So this season to be where we are is an important step but, when you are there, you have in the back of your mind the little feeling that you can still do it. You think you can, you think you can, but the reality is different."