Spring Training is into the second week at the Peoria Sports Complex, and leading up to the first Cactus League game, MLB.com will take a closer look at the 2010 team, position-by-position. Today: bullpen.

When the Mariners started playing Cactus League games a year ago, the bullpen was one question mark after another.

Who would replace J.J. Putz as the closer?

Who would be the late-inning setup men for the eventual closer?

Would there be any left-handers in the bullpen?

Was right-hander and former first-round Draft choice Brandon Morrow a starter or a reliever?

And, when camp ended, just how good could this bullpen be when two non-roster rookies made the 25-man Opening Day roster?

It took awhile, but the bullpen eventually fell into place quite nicely and finished the regular season with a 3.83 ERA, the third lowest in the American League.

Of all the surprisingly good things that happened to the Mariners last season in returning the franchise back to respectability with a big league-best 24-win improvement from the previous season, the relievers probably deserve as much credit as anyone.

"We knew all along that it was going to end up exactly that way," said a smiling Rick Adair, the team's pitching coach. "They are a unique group, to say the least."

And guess what?

Just about everyone is back this season and there is no reason to think the bullpen in 2010 would not be as good, if not better, than the one in '09.

Starting from the back of the bullpen, right-hander David Aardsma returns as the closer with a resume that now includes 38 career saves. When the '09 season started, he had no big league saves in 128 appearances.

He moved into the high-pressure job in mid-May after Morrow sustained back-to-back blown saves against the Rangers in Arlington and blossomed.

Acquired in an under-the-radar trade with the Red Sox for Minor League pitcher Fabian Williams, Aardsma converted 38 of his 42 save chances and set a club record for with 18 "quality" saves -- entering a game with the tying run in scoring position or protecting a one-run lead for at least one inning.

His 90.5 percent save success rate was the fifth best in the AL.

Right-hander Brandon League, acquired from the Blue Jays for Morrow, probably will be one of the late-inning setup men, along with holdover right-handers Mark Lowe and Sean White.

White's best season ended early because of tendinitis in his right shoulder.

But he looks good so far this spring.

"He really worked hard," Mariners manager Don Wakamatsu said. "I saw the heavy sink that he showed last year."

Another right-hander, Shawn Kelley, has the inside track on one of the bullpen jobs, but it most likely will take most of Spring Training for the bullpen to be finalized.

The departures of Miguel Batista (free agency) and Chris Jakubauskas (claimed by the Pirates) could create at least one opening, that of the long man, which could be filled by a left-hander, possibly Garrett Olson or Jason Vargas.

The Mariners want to get a good look at right-hander Josh Fields, the organization's top Minor League bullpen prospect.

"He looks bigger and stronger than he was last year," Wakamatsu said. "He's probably at least 10 pounds heavier and has a little swagger to his step this year. He's more confident."

But earning a spot in the six- or seven-man bullpen will be a chore for most of the inexperienced relievers -- including Fields -- in camp.

Veteran right-hander Chad Cordero, who is in much better shape this year, could pitch well in the Cactus League, not be on Seattle's Opening Day roster, but land a spot with another big league team.

But the focus going into the game portion of camp is the holdovers.

"The thing we are trying to emphasize is to keep building on exactly what we did last year," Adair said. "And if it's what we did last year, then it probably is going to be pretty good.

"Aardsma looks the same, acts the same, and works the same. Lowe is exactly the same. Kelley is good and looks healthy again. Whitey is in good shape and is working extremely hard."

The Mariners were noted for being a close-knit team last season, and no one was closer than the relievers. They walked to and from the bullpen together, stood side-by-side during the national anthem, kidded each other, worked hard and had fun together.

They were a unique bunch, all right.

"From the outside looking in, it's almost like, 'What is going on?'" bullpen coach John Wetteland said. "We wait for each other, we walk with each other. Sometimes Lowe would say, 'Let's walk backward for 10 steps and we'll all turn around together.' Is it all all silliness, yeah, absolutely, but everybody does it so it is togetherness, and nothing can beat that."

Get ready for more togetherness this season and always with a purpose.

"We have fun out there, but when it comes to work, they get after it," Wetteland said. "I chart every pitch of every game and will look around and every one of them is into the game.

"I don't like the word 'change,' but I do like the word 'adapt,'" Wetteland said. "It's important to stay ahead of the hitters, and that might mean thinking a little differently, being prepared to give a new look. You don't have to throw another kind of pitch, but you do have to make subtle changes in the way you pitch hitters you faced a year ago."

"Looking back to what he had at the beginning of Spring Training a year ago," Wettleland said, "Rick and I didn't know a lot about these guys and, you know, it's hard not to feel a little emotional when you look back and see what they accomplished.

"Rick and I believe in the old song, 'accentuate the positive and eliminate the negative.' That's what we teach."

And if last season is an example, it works.

Next: Designated hitter/bench.