Jerry Rice knows all about "contrasting".

It's a rehab technique in which an athlete soaks an injured body part first in a hot whirlpool, then in a tub of ice. As Rice surely knows by now, the worst part always comes at the end. Leaving the soothing warmth of the hot whirlpool for the bitter cold of the ice tub can be nothing short of painful.

The same can be said for leaving the 49ers. Even though it's no longer football's version of Shangri-La, the house that DeBartolo built is still a special place. I thought of Jerry after speaking to another former Niners teammate -- Merton Hanks.

The last time I saw Hanks was after the Seahawks had defeated the Raiders in October 1999. As his teammates celebrated behind him, Hanks silently dressed in front of his locker. It was impossible to ignore the air of melancholy that enveloped him that evening. "I liked the city and my teammates," Merton told me the other day. "But I just wasn't having any fun." He retired the following year.

I spent the 1992 season in San Francisco, and I wonder how anyone who played for those dominant teams could possibly have fun anywhere else. The Niners mystique extended beyond the five Lombardi Trophies and annual dominance of the NFC West. Staying at the best hotels, having your own room on road trips, getting pizza every Monday after a victory -- it all helped sustain a joy that can easily fade when you're getting paid to play. After the Niners released me in '93, I found myself in Cincinnati, surrounded by less-than-captivating scenery. The state-of-the-art practice facility, with swimming pool and racquetball courts, had been replaced by a crumbling edifice located under a bridge.

Don't get me wrong. I still felt blessed to be a part of the league, but going to practice no longer felt like children at play. It just felt like men at work.

I'm not saying Rice won't enjoy playing for the Raiders. It's an organization that welcomes a player who's still hungry after 16 remarkable years. At his first press conference, Rice quipped how he looked "damn good" in the Raiders' cool silver and black. That may be true, but I think sometime this fall, he'll ache for the warmth of that scarlet and gold.

Alan Grant, a former NFL defensive back, writes football for ESPN The Magazine. E-mail him at alan.grant@espnmag.com.