Barcelona forward Lionel Messi is facing a race to be fit for Sunday's La Liga clash with Athletic Bilbao.

Messi picked up a thigh injury during the latter stages of last week's 2-2 draw with Valencia in the league.

The Argentine did appear as a substitute during Wednesday's 1-1 draw with Real Madrid in the first leg of their Copa del Rey semi-final, but has hardly trained this week.

According to Marca, Messi was again missing from the main group on Friday, with the attacker instead doing more recovery work in the gym, placing his involvement in the Bilbao clash in severe doubt.

Messi has scored 29 times in 28 appearances for Barcelona this season, including 21 goals in 20 La Liga games.

The Spanish champions have another five games before the end of the month, including a trip to Lyon for the first leg of their last-16 Champions League clash.