Mancini is expected to drop Nasri for the trip to Newcastle on Saturday with the Italian unhappy with the £24 million player's contribution during the 3-2 defeat against Manchester United last weekend, says the Telegraph.
Having criticised Nasri following the United game, Mancini has made it clear to the player that he must act "differently next time". The manager said: "Someone asked how many people were in the wall. Three? I said, no, two and a half because Samir turned when Van Persie shot.
"It was a mistake. We did a mistake, but it is finished. We can't change this, but it's important that next time it will be different. I think Samir knows this, but there is no problem. Everyone can do a mistake. It's impossible to be perfect. You never know - you can have one person in the wall and they hit it into the stand or you can line up five and they put it in the top corner. It was just one of those things, we don't blame him."