The Belgian managed goals in his first three matches at his new club and has been excellent in midfield.
However, the 23-year-old has been criticized for his attitude when he was an Everton player.
Ex-Toffees star Michael Ball wrote in the Liverpool Echo, as his old team prepare to take on Villa on Saturday: "I’m looking forward to seeing Tim Iroegbunam and Amadou Onana going head-to-head because despite his lack of experience and their respective price tags, the new lad has shown more already at Everton than Onana ever did. Onana is a fantastic player, but it just felt like the wrong team at the wrong time for him and he just didn’t fit.
"Tim will want to go back to his old club and prove a point and say: 'you shouldn’t have sold me'. We know Onana's strengths, he's powerful and will want to control the game by getting on the ball very early but we also know his weaknesses so can we exploit them? He can switch off, he doesn’t like tracking back, he can be sloppy in possession at times and will take chances.
"Onana came with a lot of bluster about where he wanted to be in his football career but didn’t hit the heights expected of him, maybe through a combination of how we played, and his style didn’t suit the system too much. Fighting near the bottom of the table probably didn’t get the best out of him."