Barcelona midfielder Andres Iniesta has emerged as a doubt for the second leg of his side's Champions League last-16 tie with Chelsea due to a hamstring injury.

Iniesta was forced off 34 minutes into the first half of the 1-0 win over Atletico Madrid this afternoon, having initially attempted to carry on after picking up the problem in the 20th minute.

Barcelona will welcome Chelsea to Camp Nou on March 14 looking to book their place in the quarter-finals, and manager Ernesto Valverde admitted that they would be losing an "irreplaceable" player should he be ruled out of the contest.

"Without Iniesta we lose a unique player, irreplaceable," he told the club's official website.

"It's difficult to find a substitute for him because there is no-one like him in the world. Let's hope the injury is nothing serious."

The tie is currently level at 1-1 after Lionel Messi's equaliser at Stamford Bridge last month.