Former Arsenal midfielder Paul Merson has warned Manchester United that new signing Odion Ighalo "could be the biggest laughing stock the Premier League has ever seen".

Ighalo joined United in a surprise deadline day loan move at the end of the January transfer window, signing a short-term loan deal until the end of the season from Chinese Super League club Shanghai Shenhua.

The 30-year-old has spent the past three years playing in China and has not played a competitive match since December 6, but he does have past experience of the Premier League having scored 16 times in 55 appearances in the competition while at Watford.

Merson believes that the signing is a major risk for Ole Gunnar Solskjaer which could cost the United boss his job should it backfire.

"Odion Ighalo could be the final straw at Manchester United. If that signing is a disaster then Ed Woodward and Ole Gunnar Solskjaer are in big trouble. Don't get me wrong. He could rediscover the form he once he had at Watford and be a huge success. But he could be the biggest laughing stock the Premier League has ever seen," Merson wrote in his column for the Daily Star.

"Only time will tell. But remember, the last time he was here he only scored once in 18 games before Watford sold him and he'll have gotten lazy playing in China. I've heard people compare it with Henrik Larsson because nobody expected him to still be any good when United signed him either.

"But Larsson had been world class. He had scored goals in major tournaments and won big trophies. And he still had his finishing and his movement. Ighalo doesn't have any of that on his CV and he's coming into a struggling team. The biggest one he's ever played for.

"It's a big ask, and if it all goes horribly wrong it will just pile more pressure on the manager because you're always judged on your signings as well as your results."

Ighalo could make his United debut when Solskjaer's side return to action away to Chelsea on February 17.