He's also pitching better than ever, having not allowed a run in his previous nine outings heading into the Mariners series, and his Friday night outing in Anaheim might have been the best of his career.
While working 1 2/3 innings of a victory over the host Angels, Wuertz struck out all five batters he retired, the final one with his signature slider to give him 100 strikeouts in 76 2/3 innings this season.
"He's been ridiculous," marveled rookie All-Star closer Andrew Bailey. "He's been pitching really well all year, but what he's doing at the end here, wow."
With a 1.01 ERA over his last 24 outings prior to Tuesday, Wuertz, a right-hander acquired in a trade with the Cubs last offseason, is closing the year even better than he started -- and he was certainly no slouch early on, posting a 2.13 ERA in 12 April appearances.
His only extended struggles this season came in July, when he had a 5.93 ERA in 12 games, but he bounced back with a 1.26 ERA in 14 August appearances and had a 0.73 ERA through his first 10 games in September.
"Knock on wood," Wuertz said before Tuesday's game. "I've always had that pride of finishing the season strong."
Asked how he's managed to stay effective despite the heavy workload, Wuertz, a 30-year-old Minnesota native who made his big league debut with the Cubs in 2004, cited reasons both mental and physical.
"You really have to concentrate on the amount of work you do and figure out the best way to stay in shape throughout the year," he offered. "Things like monitoring the amount of throwing you do, how much you do in the weight room, how you warm up before you go into a game. All of that's part of it. You don't want to do too much, you don't want to do too little. Some days you throw a little more, some days you throw a little less.
"It's a fine line, but I've found something that works for me."
And he's sharing it with his less-experienced buddies in the bullpen.
"It's something I've been trying to stress with some of the younger guys," he said. "It takes a while to figure out what works for you, and everybody's different, but we do talk [a lot]."
Bailey is among those who have benefited from the advice of the bullpen's oldest and most veteran member.
Wuertz's most significant message? Something along the lines of, There are plenty of heroes in the world. Don't try to be one of them.
"The most important thing [he tells us] is to just be honest with yourself," Bailey said. "Don't push it. Don't be afraid to ask for a day off if you need one. He's been great all year, talking to us about all sorts of things. He's a really valuable guy to have on a staff, and not just for what he does on the mound."
With his lights-out finishing kick, Wuertz's value is most certainly increasing. He's one of the premier setup men in the American League, and that should net him a significant raise for 2010.
Eligible for arbitration this offseason, he's making a reported $1.1 million this year.
Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.