Englewood, CO -- (Sports Network) - Denver Broncos center Tom Nalen is scheduled to have left knee surgery on Thursday.

Following Wednesday's practice, Broncos head coach Mike Shanahan revealed that the veteran will have the knee scoped, in hopes that it will clear up the soreness which has largely kept Nalen out of training camp.

This procedure follows a previous arthroscopic surgery Nalen had back in June to repair torn cartilage in the same knee. After participating in the first week of camp, he had to cease activity due to soreness.

Shanahan said he hopes the surgery will enable Nalen to be healthy for the team's season-opener September 8 at Oakland.

The 37-year-old is heading into his 15th season with the Broncos. A torn right biceps muscle ended his 2007 season after five games, but he appeared in 64 consecutive regular-season contests from 2003-06.

A five-time Pro Bowl selection, Nalen was a seventh round pick of Denver in 1994 out of Boston College.