Romelu Lukaku is pushing for a move back to Inter Milan.
The Belgian striker has struggled to settle in his second spell at Stamford Bridge and Chelsea seems to have made quite an expensive mistake.
They paid £97.5million for his services to Inter Milan last summer but could be allowed to leave on loan in this transfer window.
He registered only eight goals last season and Tuchel often used Havertz ahead of Lukaku towards the end of the season.
Inter Milan are currently favourties to potentially land their former star on a season-long loan.
“His performances weren’t really good enough. It looks like he’s lost his confidence,” O’Hara told talkSPORT.
“I think Lukaku is one of those players who needs to have an arm around him by the manager to really give him that belief. Thomas Tuchel didn’t give him that.
“It’s been an absolute disaster of a signing. I thought he was going to be the final piece in the jigsaw.”