Barcelona forward Luis Suarez is set for a lengthy spell on the sidelines after the Spanish champions announced he is to undergo surgery to treat a knee problem. A statement from Barca on Saturday said Suarez would be treated for an injury on the external meniscus on his right knee on Sunday by club doctor Ramon Cugat and after the procedure the club would release further details on when he will return. The Uruguay forward, 32, has made 23 appearances for Barca this season in all competitions, scoring 14 goals. He completed 90 minutes in Barca’s 3-2 defeat by Atletico Madrid on Thursday which saw them exit the Spanish Super Cup in Saudi Arabia. Suarez underwent surgery on the same knee last May, which forced him to miss the Copa del Rey final defeat to Valencia, although he recovered in time to feature for Uruguay in the Copa America.