Maurizio Sarri admitted he was forced to throw Eden Hazard into action in a bid to rescue the Europa League quarter-final first leg at Slavia Prague.
Chelsea head coach Sarri concedes he did not want to use Hazard at the Sinobo Stadium, but the Blues' lacklustre showing forced his hand in the second-half.
Marcos Alonso's late header saved Chelsea's night, with the Blues now expected to complete the job in next week's second leg and reach the semi-finals.
Sarri's men face Liverpool at Anfield on Sunday in a key battle in their bid for a top-four Premier League finish, with Hazard doubtless now not as fresh as originally planned.
Asked if he had always planned to bring Hazard off the bench, Sarri replied: "No, at the beginning of the match I wanted him on the bench because I thought that, probably, the match was really very difficult.
"Probably I'd need to use him. Of course, if at the end of the first half we were 1-0, I wouldn't have used him."
Chelsea failed to gel in a side showing seven changes from Monday's 2-0 league win over West Ham.
Sarri warned his players to expect a testing second leg, despite the Blues being clear favourites to progress.
"We need to think that the second leg will be difficult because these opponents are really very dangerous also away. Like in the round against Genk.
"And so we need to be careful. It's very difficult to face them. Really very difficult.
"I'm really happy with the result. Also with the performance because, in this moment, we are able to suffer. In the past we were not able to suffer in the difficult moments of the match."
Chelsea rested Callum Hudson-Odoi in Prague, with Sarri unsure whether he will start at Liverpool.
Asked if Hudson-Odoi will start, Sarri said: "Oh, I don't know. But in my opinion he needed to rest. And so, in this match, he was out.
"But of course he is in my mind for the next match, but I have to see the last two training (sessions)."
Chelsea's security staff identified three supporters and denied them entry to the match after their part in a social media video including a racially abusive chant involving Liverpool's Mohamed Salah.
"Of course it's right that the club has a very strong decision. I think that's right," Sarri added.
