West Ham co-owner David Sullivan says Slaven Bilic will sign Alex Song if he passes medical

West Ham United co-owner David Sullivan has confirmed the club have a deal in place to sign Alex Song from Barcelona. Song, 26, spent last season on loan at the Hammers and did enough to encourage the club to extend his stay into the 2015-16 season.

The Premier League side have been in talks with Barcelona throughout the summer but had been unable to reach an agreement with the player, whose current knee injury has complicated matters. But speaking to the Knees Up Mother Brown podcast, Sullivan confirmed the Hammers have reached a breakthrough, although the move will depend on the ex-Arsenal midfielder proving his fitness.

"We have a deal in place with Alex Song subject to a medical," Sullivan said. "If the medical is okay, we will take him. He is injured at the moment, which is something you've got to weigh up. But we've got until 1 September to make a decision."

Sullivan admits that Song's injury record means any permanent deal will see the club taking a gamble. "He's a player we all admire and we just hope that the medical shows he is in a sufficient state for us to gamble. He couldn't physically pass a medical tomorrow, but if the medics say it is just a technical thing and he's only a couple of weeks away you'd take the gamble and hope they are right."

Developments in West Ham's bid to bring Song back to the club emerge just after the club confirmed the loan departure of Diego Poyet. The 20 year- old has joined the Championship side – subject to Football League clearance – on loan until the end of the season, where he is expected to have a key role in the Dons' midfield.

Poyet, who featured frequently for Hammers boss Slaven Bilic in their Europa League campaign, has not played under the Croatian in the Premier League so far this season.