Michael Kirkman most experienced lefty in 'pen

Darren Oliver is now with the Toronto Blue Jays. Michael Gonzalez remains a free agent.

That leaves Michael Kirkman as the Rangers' most experienced left-handed reliever with pitchers and catchers set to report next month. Experience for Kirkman is defined as 29 major league regular-season appearances as well as three in the postseason.

"We know we've got some kids that throw from the left side that will be in camp. There's always moves made during spring training. There's moves made right before opening day. We've got time," Rangers manager Ron Washington said after Tuesday's winter pitching camp at Rangers Ballpark in Arlington.

Kirkman began last season 0-3 with a 6.40 ERA in seven starts for Triple-A Round Rock. He then went 3-0 with a 3.98 ERA in 20 relief appearances. He also made 15 relief appearances for the Rangers in three stints last season, compiling a 6.59 ERA (20 earned runs in 27.1 innings).

Kirkman views last year's rough start as a blessing in disguise.

"I think it was actually a good thing because it made me work harder," Kirkman said. "It made me see where I was really at and it let me see where I wanted to be, what I needed to work on."

Kirkman is participating in this week's on-field workouts, strength and conditioning sessions and classroom work. The Rangers told him in December that he would be competing for a job in the bullpen rather than the rotation. Pitching coach Mike Maddux is monitoring the development of the 25-year-old.

"Michael looked very good today," Maddux said. "We made a little mechanical adjustment with him. Mike's one of those guys blessed with good stuff, man. Good arm, good fastball, good breaking stuff, and it's just a matter of him maturing and being more consistent in what he does and more consistent within the delivery will lead to more consistency in the execution."

On the current 40-man roster, the other lefties with major league service time in the bullpen are Derek Holland and Matt Harrison. Of the two, one may wonder if Harrison ends up in the bullpen if Yu Darvish signs with the Rangers.

An intriguing lefty on the 40-man roster is Martin Perez, who is one of the top prospects in baseball. How about the 20-year-old beginning his MLB career as a reliever?

"Could be, could be, Maddux said. "And, that's one thing that we can nominate guys, but I think guys have to earn their own spots and they create their own roles."

Minor leaguers Robbie Ross and Ben Snyder are among the non-roster spring training invitees. Are lefties a necessity for the big club?

"No. It's not a necessity, but we certainly would like to have them down there," Washington said. "We will do what we have to do. If we have to break camp without it, then we will break camp without it."

There's still plenty of time before the first pitch of 2012, but this is certainly a story line to monitor.