Inter Miami fullback Kieran Gibbs has questioned Arsenal's swoop for Kai Havertz.
The Germany attacker left Chelsea this week for Arsenal in a £65m deal.
But former Gunners fullback Gibbs told The Sun: "A £70 million signing is a signature signing.
"For that, I want someone who when things are going bad he's going to put the team on his back and say don't worry boys I've got this. At first sight, I don't see it. Right now, I don't see it.
"That role he's going to play it is basically a replacement for Xhaka and that's where I think Mikel sees him. I don't know if he's physical enough to be in there, I don't know if he's got the ability to use his body in situations to get out of trouble or the technical ability to play in tight areas."