Pablo Zabaleta believes Samir Nasri can provide a creative spark for West Ham if he is given time to regain his fitness.
The French midfielder, who has not played competitive football in 18 months, is training with West Ham in a bid to win a contract with the club.
Zabaleta knows Nasri well from their time together at Manchester City, where both played under current West Ham manager Manuel Pellegrini, and he feels the 31-year-old still has plenty to offer.
"Manuel [Pellegrini] knows Samir very well from his time at Manchester City," Zabaleta said.
"We need players with his quality, especially because also we lost two key players who brought quality into this team - Manuel Lanzini in the summer before the World Cup and then [Jack] Wilshere, who is very close to coming back to the team.
"On the ball [Nasri] is fantastic. He is one of those players who can give to the team some possession and play between the lines to help the attacking players to create chances."
Nasri was banned from football for breaching World Anti-Doping Agency (WADA) rules in 2016 after he visited an intravenous treatment centre in Los Angeles, but he can play again from January 1.
"Samir needs a bit of time," Zabaleta said. "He has not been football training for more than a year but sometimes those players are technically very good so he probably needs to focus more on his fitness levels than his passing and all this.
"We know Samir and his quality. When he is fit he is on a different level. He is a fantastic player.
"Hopefully he can reach his best fitness level. He has to feel physically good because we know that the Premier League is so demanding physically."