Champions League Injury Update

Lionel Messi scored for Barcelona in the Copa del Rey quarterfinal win over Malaga at the weekend, but he left the field eight minutes from time after picking up an injury.

Barcelona assistant head coach Jordi Roura told the club's official website that the leg injury was nothing serious, as ESPN reported.

The Argentina forward is unlikely to miss the Champions League last-16 tie against AC Milan, but other clubs in the tournament are waiting anxiously on news of their injured players.

Here we take a look at the injury situation for some Champions League competitors.

Iker Casillas, Real Madrid

Real Madrid will be without first-choice goalkeeper Iker Casillas for the Champions League last-16 first leg against Manchester United, and his participation in the return game is also in doubt.

The Spain No. 1 broke a bone in his hand during the 1-1 draw with Valencia in the Copa del Rey quarterfinal last week and has been ruled out for up to 12 weeks, reports Goal.com.

Casillas was hurt when teammate Alvaro Arbeloa kicked his hand while trying to clear the ball.

Real have moved to cover Casillas' absence for the next three months by signing Diego Lopez from Sevilla.

Massimo Ambrosini, AC Milan

AC Milan midfielder Massimo Ambrosini is facing an anxious wait on a thigh injury ahead of the Champions League tie against Barcelona.

The 35-year-old picked up a thigh muscle problem during the goalless draw with Sampdoria in Serie A two weeks ago and has been ruled out for a month.

The news of Ambrosini's injury comes after fellow midfielder Nigel de Jong was ruled out for the rest of the season with an Achilles' tendon problem.

Darren Fletcher, Manchester United

Manchester United midfielder Darren Fletcher will miss the rest of the Champions League campaign after undergoing surgery to resolve the bowel condition that saw him miss much of last season.

The Scotland international made his first appearance since December 2011 when he played in the group-stage match against Galatasaray in September, but the chronic condition has not cleared and needs further treatment.

Fletcher was an unused substitute in United's Champions League triumph in 2008 but missed the following year's final defeat to Barcelona through suspension.

Fletcher featured five times for United during the group stages this season.

Neven Subotic, Borussia Dortmund

Borussia Dortmund defender Neven Subotic is a major doubt for the Champions League tie against Shakhtar Donetsk next month.

The Serbia international tore muscles in his calf during a friendly win over Albacete earlier this month and has been ruled out for up to six weeks.

Brazilian defender Felipe Santana has deputised for the 24-year-old Subotic since the defender's injury.

Christoph Moritz and Ibrahim Afellay, Schalke

Schalke have suffered a double-injury blow as they prepare for the Champions League tie against Galatasaray next month.

Holland international winger Ibrahim Afellay, who is on loan at the Bundesliga club from Barcelona, had just recovered from a hamstring problem when he tore a thigh muscle three weeks ago, which will rule him out for two months.

Midfielder Christoph Moritz picked up a knee ligament tear during a friendly win over Al-Sadd earlier this month and will be out for five weeks, according to a report on uefa.com.