MADRID, Sept. 22 (Xinhua) -- FC Barcelona has suffered a double injury setback on Monday with the attacking midfielder Fermin Lopez has suffered a muscle injury, while Spain international Gavi will need exploratory surgery on a knee problem. Tests carried out on Monday have shown he has suffered "an iliopsoas muscle injury in his left leg. There was worse news for Gavi after the club also confirmed on Monday that he would "undergo an arthroscopic examination," on his right knee to attempt to resolve a long-standing problem. Barca reported on Monday that the decision to operate came after the player, "underwent intense sporting stress tests after finishing his conservation course of treatment for the radial injury to the internal meniscus in his right knee." The club didn't announce how much longer this would sideline Gavi for, merely saying it would release an update "once the procedure has been carried out."