Ferran Torres disappointed many fans with his performance against Atletico. The Spaniard was brought on in the 57th minute and was sent off in the second minute of added time.
His and Stefan Savic's WWE audition did provide entertainment value but fans would have preferred Ferran contribute with a goal or an assist.
Yet despite a seemingly poor display, Xavi was happy with the 22-year-old.
"It is also important to win without Lewy, because he is a key player," the Barca manager said post-match.
"We have missed him under pressure. Ferrán has done that job when he came out, but Lewy is a very important player for us.
"With Kessie and Ferran [on], we were able to play in the opposite half again."
When Kessie and Torres were introduced, Barcelona indeed managed to get the ball away from their box and made a few dangerous attacking moves.