Willian defended the awarding of a penalty for a foul on him by Qarabag captain Rasad Sadiqov in Chelsea's 4-0 Champions League victory.
Sadiqov was shown a straight red card following the incident and Eden Hazard converted the ensuing penalty kick, putting Chelsea on course for a victory that confirmed their place in the competition's knock-out stage.
The contact between Sadiqov and Willian looked slight but the Brazil international, who scored twice later in the game, said he felt the decision was correct.
He told BT Sport: "There was a little bit of contact. For me, it was penalty.
"I was happy to score two goals, and we deserved to win. We played well from the beginning."
Liverpool are up next in the Premier League and Chelsea coach Antonio Conte started the game with the likes of Gary Cahill and Alvaro Morata among the substitutes, while Hazard and N'Golo Kante were given 65 and 75 minutes of game time, respectively.
Willian explained the selections, saying: "We need all players to be ready for all games. We play every three days so we have to rest."
Hazard said Conte's squad rotation would stand Chelsea in good stead against Liverpool.
"We have a big game on Saturday," he said. "Some players played only 60 or 65 minutes so we are ready for Saturday.
"We needed a response. We did everything well. If they [Qarabag] scored then the game is maybe different.
"We scored four goals and did well."
On his link-up play with Willian, which was at the heart of some of Chelsea's most effective play, Hazard added: "It's easy to play with this kind of player."