Arsenal and Costa Rica forward Joel Campbell out for six months

Arsenal forward Joel Campbell could be sidelined for up to six months after suffering a serious knee injury on international duty with Costa Rica.

Campbell was part of Costa Rica's squad at the Gold Cup but was injured during the team's 1-1 draw against Canada and told reporters would need surgery to repair a torn ligament.

"It is sad and difficult to have to leave the national team," Campbell said on his personal website. "I gave it everything, as I always do. Now I have to think about my recovery to come back stronger than ever."

The injury also complicates things for Arsenal, who were expected to entertain suitors for Campbell this summer after he spent last season on loan at Sporting Lisbon.

Campbell joined the Gunners in 2011 but has spent most of his time since then on loan at various clubs around Europe. He was only a regular part of Arsene Wenger's team during the 2015-16 season, when he made 30 appearances in all competitions but failed to lock down a permanent first-team role.

With his contract expiring next summer, Arsenal could now be forced to keep him on their books during his rehabilitation process before letting him leave on a free transfer.