Maurizio Sarri said Olivier Giroud remains a "very important" player for Chelsea after his hat-trick against Dynamo Kiev.
Giroud's triple took him top of the overall goalscoring charts for this year's competition, as Chelsea raced into the quarter-finals with a 5-0 win in Ukraine and an 8-0 aggregate scoreline.
The striker has found himself on the fringes of the Blues' first team in the Premier League since the arrival of Gonzalo Higuain on loan in January, but Sarri told reporters after the game he remains an important figure in his plans.
He said: "In the last period, every time he has been on the pitch, he was able to play really very well. He has scored nine goals in this competition.
"Olivier is, for us, a very important player. I am really very happy for him and for the hat-trick, and I am really very happy with him."
Sarri was equally delighted with the performance of his side, who did not let their 3-0 lead coming into the match deter them from equalling their biggest European away win since the 1970s, scoring five on the night in Ukraine without reply.
He said: "We started very well, I think, and we wanted to start in this way because it was really very important to score after the result at Stamford Bridge.
"We were able to score after five minutes. So, for the opponents, it was really a very difficult situation. I think that we played a very, very good first half. In the second half, we managed the result. But I think [it was] a wonderful performance for 90 minutes."