The Minnesota Vikings might not have to play another game to clinch a playoff spot.

San Francisco is the last opponent of the Vikings' rocky regular season, and with Warren Moon nursing a sprained knee, Minnesota would prefer to avoid a must-win situation next Monday night.Especially after Saturday's 41-19 loss at Detroit, a game in which the Vikings (9-6) could have locked up the NFC Central title. Instead, they were badly outplayed.

"We're not thinking a lot about the 49ers right now, we're just trying to get over that game," coach Dennis Green said Sunday. "When you go in and you have some high expectations you've got to go through the right process getting it out of your system.

"Otherwise, it'll still be there, and we don't want it there the next time we play."

The 49ers (13-2) already have clinched home field advantage and might limit the use of some key players, including Steve Young and Jerry Rice, against Minnesota.

The Vikings, tied for first with the Bears and Lions, will be assured a playoff spot if Detroit, Chicago, Green Bay or Arizona lose next weekend.

If the Bears, Lions and Packers all lose, the Vikings win the division no matter the outcome of their last game. However, if all four teams win and the Vikings lose, they will miss the playoffs.

Moon, who sprained a medial collateral ligament, was limping Sunday but in good spirits. He originally feared he had broken his leg, and the knee injury was less severe than it might have been.

"I definitely wanted to go back in, because I don't have a lot of next weeks," Moon said. "I can't be waiting on next week all the time. At the point we're at in the season, we need every able body out there."

Brad Johnson replaced Moon, completing 14 of 29 passes for 104 yards. Green avoided questions about whether Johnson or third-stringer Sean Salisbury - a part-time starter last year - would play if Moon was unavailable for San Francisco.

Moon's availability might depend on the game's significance. He might not be needed at all if Minnesota hadn't played so poorly against the Lions.

The Vikings trailed 27-13 when Moon was hurt, but pulled within eight after a pair of field goals. Then they fell apart.

"It was very depressing watching it, because a lot of things just gave way," Moon said. "We lost some of our poise, something I really hadn't seen us do since I've been here."