BARCELONA, Spain (AP) — Lionel Messi, grimacing in pain, was taken off the field on a cart with a knee injury as Barcelona was held to a 0-0 tie by Benfica in a Champions League match on Wednesday night. With Barcelona already assured of advancing to the second round, Messi entered as a reserve in the 58th minute.

Messi’s left knee collided with the right handof Benfica’s Artur as he ran onto Gerard Pique’s long pass and tried to round the goalkeeper in the 85th minute.

Messi took a left-footed shot from an angle, then fell to the field in pain. He rolled onto his back and held the knee, then was loaded onto a cart.

”Messi has a bruise on the outside of his left knee,” Barcelona said on its Twitter feed. ”He’ll undergo further tests to determine the exact extent of the injury.”

A three-time FIFA Player of the Year, Messi has 84 goals for Barcelona and Argentina this year, one shy of Gerd Mueller’s 40-year-old record for most goals in a calendar year for club and country.