Arsenal are confident of agreeing a deal to sign Martín Zubimendi in the summer and will step up attempts to bring in a striker this month after confirming Gabriel Jesus has sustained an anterior cruciate ligament injury that will rule him out until next season.

Talks over Zubimendi, who turned down a move to Liverpool last year and opted to remain at Real Sociedad, are understood to have progressed in recent days, with the Spain midfielder thought to be keen to join. The 25-year-old, part of the Spain squad that won Euro 2024, has a €60m (£51m) release clause that will have to be met.

Related: Arteta sounds warning as he admits Havertz affected by social media abuse

Arsenal are looking to strengthen in midfield, with doubts over whether Thomas Partey and Jorginho will be offered new contracts to take them beyond this season. The club signed Mikel Merino from Real Sociedad in August and have a good relationship with the Spanish club’s hierarchy. Real Sociedad’s director of football, Roberto Olabe, is believed to be a potential contender, along with Tomas Rosicky, to replace Edu as Arsenal’s sporting director.

Edu’s former deputy Jason Ayto has been leading the search for players and is trying to bring in a forward after the injury to Jesus in the FA Cup defeat by Manchester United on Sunday. Arsenal said on Tuesday assessments and scans had confirmed an ACL injury to his left knee.

“Gabby will undergo surgery in the coming days and will soon begin his recovery and rehabilitation programme,” a statement said. “We will continue to keep everyone updated with Gabby’s recovery, with everyone at the club fully focused on supporting Gabby to ensure he is back to full fitness as soon as possible.”

With Kai Havertz the only recognised striker available to Mikel Arteta, Arsenal could attempt to bring forward an anticipated summer move for RB Leipzig’s Benjamin Sesko, having courted the Slovenian last year, although the German club would prefer to wait until the end of the season to sell. Leipzig, whose move to sign Noah Okafor on loan from Milan has collapsed owing to an injury to the Swiss forward, are believed to have included a gentleman’s agreement over a future transfer fee in the new contract Sesko signed in the summer.

That could mean Arsenal turn to the European loan market for a stopgap, having filled their two Premier League loan slots by signing Neto and Raheem Sterling. Dusan Vlahovic, heavily scouted by Arsenal in 2022 before they opted to sign Jesus from Manchester City, is a potential option, although the Serbia international has been a regular starter for Juventus. The Italian club are interested in signing Randal Kolo Muani on loan from Paris Saint-Germain but face competition from Tottenham for the France forward and it remains to be seen whether they would allow Vlahovic to depart.

Arteta, who admitted before the derby at home to Tottenham that abhorrent social media messages sent to Havertz’s wife had affected the forward, said: “We are actively looking in the market to improve the squad. That’s been like that since day one. It would be naive not to do that. It’s an opportunity to improve the squad. We are looking. We are trying. Let’s see what we can do.”

Oleksandr Zinchenko may be allowed to leave Arsenal this month on loan having found his appearances restricted by the emergence of the academy product Myles Lewis-Skelly at left-back. Borussia Dortmund and Galatasaray are understood to have shown an interest in the Ukraine defender, who joined from City in July 2022.