Alaves striker Borja Baston has been ruled out of action for three to four weeks after suffering a hamstring problem.
The former Swansea City man suffered the injury, playing in the Alava Trophy, a triangular competition during the international break between Real Sociedad, Alaves and Sochaux.
Medical tests have now determined the full extent of the problem, which will see the striker miss the games against Real Valladolid, Rayo Vallecano, Levante and Real Madrid.
Pressure on out-of-form Guidetti
The 26-year-old arrived in Spanish football from Manchester City in 2015, joining Celta and he impressed during his first season, netting 12 goals for the Galician side.
Mixed form in his second season saw the goals of Iago Aspas push him to the bench and it was last season that saw him forced out on loan to Alaves, where he netted just one goal in ten games.
Despite his lack of firepower, the club opted to activate their permanent deal clause and agreed to bring him into the club this summer on a four year contract.
So far this season, Guidetti has featured from the bench, but failed to make an impact – and in total, his lack of finding the back of the net – has been extended.