Enzo Maresca confirmed on Thursday that Filip Jorgensen has replaced Robert Sanchez as Chelsea's No 1 goalkeeper as he seeks to recover momentum in the Premier League.
Spain international Sanchez, 27, has made a string of costly errors this season, including in last month's 3-1 defeat at Manchester City.
Denmark under-21 goalkeeper Jorgensen was picked to start in the 2-1 league win against West Ham earlier this month but Sanchez was back in goal for last week's FA Cup defeat at Brighton.
Maresca, whose team face Brighton again on Friday, confirmed at his pre-match press conference that Jorgensen, 22, is currently his first choice.
The Italian said his aim had been to give Sanchez "some time to recover mentally, physically".
But he added: "The idea is not to game by game change the keeper. In this moment, the last Premier League game against West Ham that we won was Filip... the FA Cup game was Robert, but our keeper in this moment is Filip."
Chelsea were just two points behind runaway Premier League leaders Liverpool in mid-December but results have dropped off sharply.
Maresca, though, believes his fourth-placed side, still on course for Champions League qualification, have made significant strides in his first season at Stamford Bridge.
"I don't think what we have done can be cancelled or can be no good, because what we have done is there," he said.
"Unfortunately we are out of both domestic cups but our journey in the Premier League has been fantastic until today, in the Conference (League) has been fantastic until today and we're going to try to finish in the best way we can."
He added: "I said already many times, don't forget that in the last two years, Chelsea has never been top four and this year we spent almost our (whole) season in the top four.
"This shows you and everyone that we are in the right direction. Now we're going to try our best to finish and to bring this club where this club belongs to be, in the Champions League."