MADRID, Feb. 4 (Xinhua) -- FC Barcelona striker Leo Messi remains a doubt ahead of the first leg of his side's Copa del Rey semifinal first leg against Real Madrid on Wednesday.

The Argentinean finished Saturday's 2-2 draw at home to Valencia, in which he scored both of his side's goals, with a slight thigh strain and although he didn't ask to be substituted as Barca chased the winning goal, he wasn't moving freely by the final whistle.

Fears that he could miss his second 'Clasico' of the campaign were increased on Monday when he missed training with the rest of the Barcelona first team squad and remained in the gym under the attention of the club doctors.

There was better news regarding French forward Ousmane Dembele. The French forward has been sidelined for the past fortnight after twisting his ankle in Barca's 2-1 win at home to Leganes on January 20th.

He also missed Sunday's training session with a sore throat and a fever, but was able to train alone on Monday and is expected to complete Tuesday's training session with his teammates.

The Frenchman is not expected to be fit enough to start Wednesday's Cup game, but everything points to him being fit enough to take a place on the substitutes' bench. Meanwhile whether or not Messi trains on Tuesday is going to be the major question for Barcelona over the next 25 hours.

Coach Ernesto Valverde was pragmatic about Messi's fitness when asked about the striker on Saturday, saying if he didn't play "then someone else will," and Valverde will no doubt remember that Barca's 5-1 win at home to Madrid at the end of October came thanks to Luis Suarez hat-trick and without Messi in the side.