FORT MYERS, FLA. – Antonio Bastardo was available. Tony Sipp also was on the market. Maybe the Brewers would have parted with Will Smith in the right deal.

The Twins could have filled their opening for a lefthanded setup man with someone with a proven track record. They passed on Sipp and Bastardo, who each will make at least $6 million this season. And they didn't land one in a trade — perhaps Smith will be available during the season if there still is a need.

And so there was one significant question mark as the Twins spring training opened Monday with 31 pitchers and eight catchers beginning formal workouts at the CenturyLink Sports Complex. Most of the everyday position lineup is known. The Twins know who their top eight starters are — and might have an idea who the best five are. But the composition of the bullpen — particularly which lefthander can set up for closer Glen Perkins — is yet to be determined.

"From the left side, you've got Glen," Twins manager Paul Molitor said, "and a lot of guys."

There are 12 of them, to be exact. All with different levels of experience and whose chances of winning a job span from good to fat.

"It's going to be an open book this spring," Twins pitching coach Neil Allen said. "There are jobs to be won. There are jobs to be had. And nothing is going to be set in stone until we sit down the last 10 days and really focus on some ideas and some directions on what we need."

There are no preferred candidates but several Twins officials have indicated that, as of now, minor league free agent Fernando Abad and prospect Taylor Rogers have the best chances to win the available lefty bullpen job.

Abad, 30, has six years of big-league experience and spent the past two seasons with Oakland. His 2014 season was excellent, as he posted a 1.57 ERA in 69 games while holding opponents to a .175 batting average. Things didn't go so well last season, as his ERA shot up to 4.15 and lefthanded hitters batted .277 against him.

Twins scouts believe Abad tipped some of his pitches, something they can address during camp. Abad thinks his struggles are from not pitching in winter ball following the 2014 season. He remained in the United States while waiting for his green card and worked out on his own. He said his arm didn't feel the same, and it led to getting pitches up in the zone and his performance suffered. This offseason, he was back with Toros del Este of the Dominican Winter League.

"It's different when I train by myself than with someone else," Abad said of being on a winter-ball team. "This year, I prepared pretty good. I played winter ball and everything changed. So I am ready to go."

Abad likes to throw a changeup, which is a good match with the pitching philosophy of Allen, who promotes throwing the offspeed pitch.

Rogers, 25, has started for most of his pro career, going 11-12 with a 3.98 ERA last season for Class AAA Rochester in 28 games (27 starts) over 174 innings. He threw another 25 innings during Arizona Fall League, where he improved his changeup. His fastball sits at 89-91 miles per hour, and he throws a sharp slider.

The Twins like that he goes after hitters, so they feel he could help out of the bullpen. Rogers isn't used to warming up quickly or pitching in back-to-back games. He sought advice on those issues from his twin brother Tyler, a reliever in the Giants organization.

"Whatever the team needs and whatever I can do is what I'll do," Rogers said. "I'm sure I'll miss starting, but as long as you are pitching, you can't really complain."

Two other candidates are Aaron Thompson and Ryan O'Rourke. Thompson had 2.11 ERA through his first 17 games with the Twins in 2015 but 10.64 over his last 24, and he didn't return after being demoted July 7. He was replaced by O'Rourke, who isn't a hard thrower, but lefties hit only .171 against him in his 27 games in the majors.

The Twins will look at other criteria as well who the lefthander will be. Can he hold runners on? Does he have a slide step? Can he get a few righthanded hitters out too? There are many things to consider as the Twins tackle the lefthanded question.

"We don't know what kind of a situational lefty we are looking for and how his stuff matches up for us," Allen said. "A lot of that will come into play during this spring training."