Arsenal will need to activate Sporting Club de Portugal striker Viktor Gyökeres’ release clause if they want to sign him in the January transfer window.

That’s according to Sporting boss Ruben Amorim, who has insisted the striker won’t be leaving unless anyone pays that figure.

Gyökeres has been shining in Portugal this season since joining Sporting in a €20m deal from Coventry City midway through the summer transfer window.

He’s managed 15 goals and seven assists in 17 games in all competitions to date, remarkable numbers that have continued his fine form from last season when he managed 22 goals and 12 assists in 50 games in all competitions for the Championship side.

It’s led to increasing speculation that some of the biggest sides in Europe could soon come calling and a report from Portugal yesterday stated that Arsenal have been scouting him extensively.

The persistent belief is that they need to add a goalscoring centre-forward to Mikel Arteta’s squad, with the likes of Gabriel Jesus and Eddie Nketiah not the regular scorer the team needs up front.

Gyökeres could fit the bill given his current scoring form, but Amorim has insisted that Arsenal, or any other potential suitors, will need to match his release clause if they want him in January.

“I can’t guarantee anything, what I can say is what they tell me and that is any player only leaves through the clause,” he said.

“It’s the only security that clubs in Portugal have. Our idea is not to sell anyone in January, because we have a full calendar, and we need all the players available. I’m calm about that.

“At this moment we are only selling due to the clause, it is a different security than last year, when Porro left in January [to Tottenham] when he was very important in our dynamics.”