Gates missed practice for a third straight day and is listed as questionable. The All-Pro has started 85 straight games for San Diego and has played through toe injuries in the past.
"My streak is on the line," Gates told the San Diego Union-Tribune. "More important is we're trying to make a run, make a push. The next few games are important to our season. I want to do whatever I can to help and not hurt the team."
San Diego will be without kicker Nate Kaeding (groin) and linebacker Larry English (foot).
Running back Fred Taylor (toe) and safety Jarrad Page (calf) will not play.