San Diego Chargers safety Steve Gregory returns from his four-game suspension this week.

Gregory was suspended four games for violating the league's substance abuse policy, during which the Chargers went 1-3.

A former undrafted free agent from Syracuse, Gregory has 160 tackles and two interceptions during his 65-game career, all of which spent with the Chargers. Gregory started the first four games of the 2010 regular season, posting a team-high 30 tackles and grabbing an interception in the Chargers' 41-10 win over the Arizona Cardinals in Week 4.

Gregory denied knowingly ingesting a banned substance, but took responsibility and apologized for it upon word coming down that his appeal had been denied.

"I was completely shocked to find out about this positive test from May during the off-season," Gregory said last month. "I have never knowingly used any form of performance enhancing substance, however as an athlete I know that I am responsible for everything that goes into my body...I apologize to my teammates, coaches, the organization, fans, and my family and friends. I look forward to moving past this and helping my team win a championship this year."

Paul Oliver has started at strong safety the last four weeks, and the team re-signed safety Quinton Teal and added veteran Tyrone Carter, who has a pair of special teams in three games since being signed in Week 5. The 3-5 Chargers will receive a roster exemption, but are expected to add Gregory to the 53-man roster prior to next Sunday's road game against the Houston Texans.