A look at a player who gave his team a significant boost in Week 15.

Matt Cassel meant a 45-point swing for the Kansas City Chiefs.

Now, that’s high energy.

Cassel showed the NFL just how tough he is Sunday, when he led the first-place Chiefs to a key win in the AFC West 11 days after having an appendectomy. It wasn't determined until just before the game that Cassel -- who was limited in practice all week -- would be able to play. He didn’t even participate in the team’s pregame warm-ups to preserve energy.

Yet, when the game started, there was no bottling Cassel. He moved and ran unlike a person who had a significant medical procedure 11 days earlier. Cassel led the Chiefs to a 27-13 win at St. Louis. After the game, many Rams players remarked that Cassel showed no signs of the physical distress he had just endured.

The Chiefs desperately needed Cassel. In the one game without him, Kansas City was pounded, 31-0, by second-place San Diego. Sunday, though, all was well again -- the efficient and underrated Cassel was behind center for the Chiefs.