Barcelona forward Lionel Messi will have tests on Monday on a possible muscle injury sustained in Sunday`s 6-0 La Liga victory at home to Athletic Bilbao, coach Luis Enrique said.Messi, who scored Barca`s opening goal from the penalty spot, was replaced by Arda Turan at halftime at the Nou Camp and Luis Enrique told a news conference he had taken the decision as a precaution.The Argentina forward and FIFA Ballon d`Or holder missed two months late last year with a knee injury but has looked close to his best in recent weeks."Tomorrow tests will be conducted, he has some mild muscle fatigue," Luis Enrique told a news conference."There was no sense in taking risks," added the former Barca and Spain midfielder. "I don`t like to risk anyone, least of all Messi."Barca`s Spain fullback Jordi Alba also had to come off in the second half after sustaining what looked like a hamstring strain when lunging for the ball.Second-placed Barca, who are two points behind leaders Atletico Madrid with a game in hand, play at Bilbao in the first leg of their King`s Cup quarter-final on Wednesday.Barca beat Bilbao 3-1 in last year`s final and the return is at the Nou Camp a week later.