That’s after Sky Sports claimed the midfielder failed to turn up for Toffees training on Tuesday.
Onana, 21, has been one of Everton’s few shining lights this term following a £33m switch from Lille last summer.
The Belgium international has made 20 appearances in all competitions.
And it’s reckoned that big-spenders Chelsea are exploring a move as they look to boost their ranks with football’s top youngsters.
However, 90min claims Arsenal have now joined the race for Onana.
Mikel Arteta is hoping to strengthen his midfield options, having already completed January moves for Brighton winger Leandro Trossard and Spezia defender Jakub Kiwior.
And he reckons Onana would be perfect to give Arsenal’s title credentials another lift.
The Gunners have now approached Everton over a deal for their star, with the Toffees open to business after being put up for sale by Farhad Moshiri.
But Arsenal will have to pay a massive £50m if they want to bring Onana to the Etihad.
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Their approach comes after the playmaker reportedly missed Everton’s training session on Tuesday.
Sky Sports says Onana was not present at Finch Farm one day after Frank Lampard was sacked.
And it’s also claimed Anthony Gordon was missing too.
His reported absence comes amid links with a move to Newcastle.
Mega-rich Toon are hoping to land Gordon for £25m plus 15m in add-ons, just six months after Everton turned down £60m from Chelsea.
And Everton have a big decision to make as they also look to appoint a new boss to save them from the dreaded drop.