Paul Merson has claimed that his former team Arsenal "are certainties" to beat Manchester United when the two teams meet at the Emirates Stadium in the Premier League on Sunday afternoon.

Sixth-placed Arsenal are currently five points behind fifth-placed Man United in the Premier League table, but Jose Mourinho's side will only have one day to prepare for the clash in London as they take on Celta Vigo in the first leg of their Europa League semi-final on Thursday night.

Merson has claimed that Red Devils boss Mourinho will make "wholesale changes" ahead of the second leg with Celta next week, and has backed Arsenal to run out comfortable winners on home soil.

"Arsenal are certainties in my opinion. It's all about timing at the end of the season and this game is perfect timing for the Gunners. United could win their next four Premier League games 5-0 and still finish fifth in the league," Merson told Sky Sports News.

"On the other hand, they might only have to win two Europa League games to qualify for the Champions League. I don't see anything but wholesale changes for Jose Mourinho for this game... I'd be shocked if any of the big guns played at the Emirates on Sunday.

"The wholesale changes put severe pressure on Arsene Wenger. They will be playing a second string side in my opinion and if they can't beat an under-strength Manchester United, huge pressure will be put on the Frenchman. He would probably prefer to be playing United's first team."

On Wednesday, Mourinho admitted that he would prioritise the Europa League over the Premier League in the final weeks of the 2016-17 campaign.