AC Milan have announced that Kevin-Prince Boateng will have to spend some more time on the sidelines after sustaining a new thigh injury.The versatile midfielder had returned from a four-week lay-off in Milan’s 4-0 Champions League victory against Arsenal last week, scoring the club’s first goal with a stunning volley.However, Boateng, who was replaced in the second half, has returned to the club’s infirmary after picking up a new muscular problem against the Gunners."Milan would like to announce that after the match against Arsenal, Kevin-Prince Boateng was diagnosed with a muscular strain in his left thigh,” a club statement read.Boateng who sat out Sunday’s Serie A match with Cesena, is doubtful for Friday’s visit of Juventus.