Messi to undergo kidney tests, will resume 1st team duties Wednesday

Barcelona superstar Lionel Messi will undergo tests over the next two days to determine the severity of kidney problems he's experienced since December, the team announced Monday.

Although the Catalan giants expect the Argentine to return to first-team duties Wednesday, his availability for the Copa del Rey tie against Valencia on the same day is unknown.

Messi was reportedly set to miss the second leg match against Valencia, and return Thursday after undergoing a minor operation to correct the issue, according to Albert Masnou from Spanish outlet Sport.

His appearance, regardless of the injury, appeared to be in doubt considering the lopsided 7-0 win Barca recorded in the first leg.

Messi was absent from the Club World Cup semifinal in December because of abdominal pains.