FC Barcelona captain and goalkeeper Marc-André ter Stegen has missed five consecutive pre-season sessions with persistent back pain and continues to train alone, according to multiple Spanish outlets. Club sources quoted by ESPN say Barcelona have encouraged the 33-year-old to leave following the arrivals of Joan García and Wojciech Szczesny, but the German international has so far declined. Medical staff are assessing whether ter Stegen requires surgery that could rule him out for about four months, Spanish media reported on Thursday. Under La Liga rules, a long-term absence would allow Barcelona to deregister the player and redirect up to 80 percent of his roughly €16 million gross salary toward registering new signings and meeting financial-fair-play limits. Head coach Hansi Flick, who is working with 36 players, plans to take 26 on a tour of Asia starting 24 July. Ter Stegen is not expected to travel, leaving García, Szczesny and academy graduate Iñaki Peña to compete for the No. 1 role during the trip and potentially into the new season.