West Ham signed the midfielder from Slavia Prague in January last year on loan before turning it into a permanent deal in the summer.
The defensive midfielder’s performances have played a key role in powering West Ham in the Premier League this season as they chase down a Champions League spot.
He has also netted nine Premier League goals this term and there are suggestions Manchester United are interested in potentially taking him to Old Trafford.
O’Hara admits that Soucek has been a brilliant signing for West Ham and his presence has transformed West Ham this season.
However, he feels if a side of Manchester United’s size want the midfielder, the Hammers are likely to struggle to keep him at the club, despite their progress this season.
O’Hara said on talkSPORT: “He has been awesome. He has transformed West Ham and what a player he has been for them.
“A great signing that went under the radar, but his performances have been absolutely exceptional.
“He has turned into a proper top player in the Premier League and West Ham are lucky to have him, but I think they might struggle to keep hold of him.
“If you are Soucek and you are having the season you are and say someone like Man United come because Man United need a player like him.
“He would come into Manchester United’s team with his energy, his runs and he scores goals.
“It’s hard to keep hold of someone when big teams like that come in for you.”
Soucek has a contract until 2024 with West Ham and the Hammers are likely to resist offers to sell him in the summer.
