San Diego enters this game tied with Kansas City for second place in the AFC West, two games behind front-running Denver. Oakland, which has lost three of its last four, is out of the hunt at 4-7.
While the game might have meant more to Morrison were the Raiders still harboring playoff hopes, but Oakland's 33-21 loss to Miami last week all but eliminated it from contention.
Thus Morrison is finding new inspiration for his return to Southern California. It comes in the form of the trying to play well in front of the countless friends and family heading to Qualcomm Stadium.
''It means a lot to go back just because I spent the last five years down there. I know the organization, the players on the team, everything,'' Morrison said. ''It's huge for me to go back.''
While playing for San Diego State, Morrison -- a four-year starter for the Aztecs and a lifelong Raiders fan -- spent many weekends at Qualcomm. If he wasn't there on a Saturday playing with his San Diego State teammates, Morrison was there on Sundays watching his beloved team play.
''I remember my first (Raiders-Chargers) game,'' Morrison said. ''It was the same deal like this. It was a Sunday night, it rained, and that (stadium) was packed. There were fights everywhere but the game on the field was the best part. The first game against them this year we were playing catch-up but I think this time it's going to be a little bit different.''
San Diego gave Oakland all kinds of problems the last time the two teams played. The Raiders, coming off a bye week, came out exceptionally flat, fell behind early and never recovered. That same pattern followed the team in subsequent home losses to Denver and Miami that killed whatever hopes Oakland had of making it to the postseason.
The Chargers head into the game winners of their last four and seven of their last nine, riding the performance of Tomlinson. Tomlinson rushed for 140 yards and had three touchdowns -- one running, one receiving and one passing -- when San Diego played in Oakland earlier this season.
In fact, Tomlinson has reserved some of his best games for the Raiders. Four of his top 10 single-game rushing performances have come against Oakland. Surprisingly, his effort on Oct. 16 this season wasn't one of them.
''Regardless of our record, we still have to prove something,'' Morrison said. ''What better way to do it than on Sunday night against a team, the Chargers, that everyone is expecting us to lose to this week.''
* Though the forecast calls for clear and sunny skies in San Diego, the Raiders spent Thursday's practice working out in the rain. Storms dumped several inches of rain on the Bay Area, though it didn't alter Oakland's practice schedule.