He's never been a fearsome, fire-breathing closer in the Goose Gossage or Jonathan Papelbon mold, but Fuentes' deceptive delivery, low-90s heater and big-bending slider have served him well over the years.
Equipped with less gas, he made it to the finish line in 2009 but never felt that he found his premium fastball after a difficult Spring Training led to a slow start.
"My velocity was down two or three miles per hour," Fuentes said. "I was 88-90 [mph], and I'd like to be 90-93. That's a big difference. I didn't have my best stuff.
"I like to throw my fastball about 70 percent of the time, and when I'm going good, I can do that. I had to go to my offspeed stuff more than usual last year.
"It's not that I pitched poorly. I just didn't pitch to my expectations. I'm an honest evaluator of myself. Sometimes, I pitch poorly. I'm always able to look in the mirror and ask, 'Could I have done better?'
"As for my work ethic, I couldn't have done anything different. I struggled to have the year I had. I learned some things that hopefully will translate into a stronger season."
Signing a two-year free-agent deal with a vesting option for 2011 after seven seasons in Colorado, Fuentes felt compelled to go the extra yard for the Angels to try to make an impression in the transition to a new club and new league.
There also was an invitation to pitch for Team USA in the second World Baseball Classic, and the left-hander wanted to be ready after enjoying his participation in the inaugural Classic in 2006.
Gearing up, Fuentes worked with a personal trainer over the winter at home in Merced, in central California, a departure from normal routine.
"I had a career year [in 2008] and, coming to a new team, I had high expectations," Fuentes said. "I hired a personal trainer to be even better -- bigger, faster, stronger. It wasn't like I was doing anything harmful, but it didn't translate to baseball terms."
Fuentes' intentions were good, but the results were questionable.
Back spasms surfaced in Spring Training, and Fuentes was forced to shut it down. He didn't pitch for Team USA and fell behind in camp, searching for command of his fastball.
The season started poorly. He was 0-2 and carrying a bloated 5.30 ERA into June when he turned it around with a perfect month -- nine saves and no earned runs in 8 2/3 innings.
More problems materialized in July (6.48 ERA in 11 innings), but a solid finish left Fuentes with his Major League-high 48 saves in 55 opportunities for a save percentage of .873 -- seventh best in the AL and better than the star he replaced, Francisco Rodriguez, forged in his debut season with the Mets.
"Percentage-wise, I'm better than that," Fuentes said. "I gave 100 percent every time I went out there. I hold my head high. I never give up on my team, and they never give up on me."
With regard to the demanding nature of Fuentes' job, the postseason offers a case in point.
Fuentes is largely remembered for giving up the homer launched by the Yankees' Alex Rodriguez in Game 2 of the American League Championship Series.
Protecting a one-run lead in the 11th inning, Fuentes delivered a fastball away that was sent into the inviting seats in right by A-Rod. The Yankees went on to win and seize a 2-0 series lead.
That was the only hit surrendered by Fuentes in October. He faced 19 batters on the big stage and got 14 outs for a 1.93 ERA. His three saves included two in the ALDS sweep of Boston and a dramatic ALCS Game 5 win at Angel Stadium that sent the show back to the Bronx.
Yet, when the Angels signed heat-dispensing righty Fernando Rodney as a free agent this past winter, there was widespread speculation that Fuentes no longer held claim to his closer's role. Rodney converted 37 of 38 save attempts for the Tigers in 2009.
Scioscia has made it clear that Fuentes remains his main man, reiterating that position on the first day of camp.
"Brian Fuentes had a terrific season for us last year," Scioscia said. "Maybe he had a couple of rough spells, but for the lion's share of the season, he was terrific. Rodney and [Scot] Shields at the back end -- that's some power arms that are going to get to him.
"We're very comfortable that Brian is going to be that guy to be a presence at the back end of the game."
Determined to show that he owns the ninth, Fuentes returned to his old offseason program and, at 34, admitted to making a small concession to Father Time.
"As you get older, backing off in your workouts can give you bigger gains," Fuentes said. "As you get older, you have to listen to what your body is telling you. Sometimes, less is more."