West Ham co-owner David Sullivan has admitted that re-signing Alex Song on a permanent basis represents a gamble on the part of the London club.
The Cameroonian midfielder spent last season on loan at Upton Park from Barcelona, making 31 appearances in all competitions.
The former Arsenal man's form tailed off towards the end of the season, however, and Sullivan has pinpointed concerns attached to the deal.
"We have a deal in place with Alex Song subject to a medical," he told the Knees Up Mother Brown podcast. "And if the medical is okay, we'll take him.
"On his pre-Christmas form he was possibly the best player we've ever signed, but after Christmas he was just another player.
"Maybe there were reasons for that and maybe we'll see the true Alex Song and maybe he'll make a huge contribution this year."
Sullivan went on to confirm that the 27-year-old is currently injured and that the proposed deal is subject to him proving his fitness.
"He's a player we all admire and we just hope that the medical shows he's in a sufficient state for us to gamble," he said.
"He couldn't physically pass a medical tomorrow, but if the medics say it's just a technical thing and he's only a couple of weeks away, you'd take that gamble and hope they're right.
"He's still got two years left on his Barcelona contract and you're signing a player on a three-year contract, so it's a huge commitment.
"He's a big earner, Alex.
"But we're quite short in that department actually, if we get an injury or two there's not much.
"So we'd like another senior pro in that position."
