Alexis Sanchez
Alexis Sanchez is confirmed to miss the start of the season after his Copa America heroicsGetty

Alexis Sanchez has returned to Arsenal training but will not be risked for the opening Premier League game against West Ham United as manager Arsene Wenger deals with a lengthy injury list.

Sanchez won the Copa America with Chile in the summer and was given extra time off to recuperate following the tournament, with Wenger having previously confirmed the 26-year-old would be absent for the opening week of the campaign. And the Frenchman has reiterated Arsenal will be without last season's top scorer but the ex-Barcelona forward has returned to training.

"Alexis is back in training but I don't think he will be involved on Sunday [9 August against West Ham], it is a bit early maybe," he told Arsenal's official website. "We have to decide that at the end of the week, but I don't think he will be involved."

Despite being given time off to recover from his heroics in the Copa America, Sanchez has uploaded two videos on to his Instagram account of him running on a beach in his homeland as he attempts to prepare for the new season.

"Alex without running around is not Alex, you know," the Gunners boss added. "You can't imagine him lying on the beach somewhere and not moving! He came back in good fitness shape so that is quite positive, but I am not surprised by that because I can't imagine him lying around for four weeks and doing nothing. That wouldn't be him."

With confirmation that Jack Wilshere will also miss the start of the new campaign with a hairline fracture suffered during pre-season training, Wenger is already faced with extensive concerns. Joining Sanchez and Wilshere on the sidelines for Arsenal's Premier League opener is Danny Welbeck and Tomas Rosicky, who have both been ruled out of the game.

Welbeck has been nursing a knee injury, which saw him miss the last six games of last term, including the FA Cup final win over Aston Villa, while a similar issue will see Czech Republic international Rosicky also absent. "We have Welbeck on a progressive recovery and Rosicky on a progressive recovery," Wenger explained. "[Welbeck] is not too far away, but he is not ready for Sunday."