Postecoglou admitted that Sarr has worked his way back into the team over recent matches.
The midfielder scored an impressive goal in a Carabao Cup win over Manchester City recently.
Speaking after a win over Aston Villa in the league, Postecoglou stated: “
They're never out of my line-up, it's different challenges along the way. But he probably played as much as anyone last year, I rate him so highly. His capacity again to work for the team but also the quality he has in breaking open oppositions with his running with the ball. I knew he'd be important today because they've got such a hard-working midfield with Onana, Tielemans, McGinn in there, Rogers.
They don't really play with wide players, they work awfully hard in that midfield area and you've got to match that. You're never going to break them open unless you do that. He just put in another enormous effort. Along with Rodri and Biss when he came on, and Deki of course.
“I'm really proud of the lads. It was an important day for us today. Because it's also the birthday of the late Ugo Ehiogu and he had a big influence on Matty Wells here at the club, I know he played for Villa but he was obviously a coach at our football club.
“Matty spoke really strongly about him. When you hear things like that, and how people affect your life, it helps give clarity to the players about what we're trying to do here. Obviously for his wife and his son probably a tough day, but hopefully they get a little bit of cheer from the fact Wellsy made it a really important point, that he may be gone but he's not forgotten.”