Often-injured Detroit Lions safety Louis Delmas has an issue with his left knee again.

Delmas underwent arthroscopic surgery on the knee in early August, forcing him to miss the first four games of the season. He left Sunday’s 28-24 victory over the Seattle Seahawks when he injured the same knee in the third quarter at Ford Field.

Delmas left with a, I don't want to call it a re-injury of his knee, but an injury to his knee," Lions coach Jim Schwartz said, according to Anwar Richardson of MLive.com. "He wasn't able to return. We'll have some tests tomorrow to see where it is."

Delmas missed five games at the end of last season and sources have said teams identified knee issues for Delmas when he was drafted in 2009, a second-round pick by the Lions. He is in the final year of his contract.

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Brad Biggs covers the Bears for the Chicago Tribune