Guardado inherited the role from C.J. Wilson, who had the job before undergoing elbow surgery earlier this month. With those two gone, Rangers manager Ron Washington said that Francisco is the clear-cut choice to handle the job.
Francisco has one of the hardest fastballs on the team, his location and control have improved as the season has progressed and he's been able to develop his split-finger fastball and his changeup.
The righty has a 3.04 ERA in his last 26 games, and opponents are 16-for-100 (.160) off him in that stretch. He has 65 strikeouts in 52 1/3 innings on the season and is fourth in the American League with 11.18 strikeouts per nine innings.
His control has also sharpened. Francisco has brought down the number of batters he's walked per nine innings from 5.76 in 2007 to 3.78 this year. He's walked 2.18 per nine innings since June 3 over 32 appearances.
"The thing I like the most about him this year is he's been consistently throwing strikes," Washington said. "He's not hurting himself because he's putting guys on the bag. If they get him from swinging the bat, that's fine. That's what you want to see."
Francisco has no guarantees beyond this season. The Rangers will watch Francisco and reevaluate him after the season is over. But he has as good of chance as anybody, maybe better.
Presumably, Wilson will be healthy in Spring Training, but the job will not be handed back to him. He'll have to earn it, and there has been some talk within the organization of turning him back into a starter the way it did with Scott Feldman.
"We're focused on August 2008," general manager Jon Daniels said. "We haven't had a chance to talk about it as a staff, and we haven't talked to C.J. We want to let C.J. get healthy, let the team perform and worry about that down the line."
The more immediate concern is filling out the roles in the bullpen behind Francisco. Jamey Wright takes over as the eighth-inning setup reliever, and Bill White is being called up from Triple-A Oklahoma to be used as a situational left-hander. The seventh inning is what worries Washington most.
Right-handers Josh Rupe, who is 3-1 but has a 4.52 ERA, and Joaquin Benoit, who missed a month because of right shoulder inflammation, will likely share the duties. Benoit was the Rangers Pitcher of the Year in 2007 for his work as a setup reliever, but his velocity is down this season because of the shoulder problems.
Dustin Nippert remains the long man, and Warner Madrigal will be used in a variety of roles while he attempts to establish himself as a front-line setup reliever.
Hamburger, 21, is a closer but a long way from the Major Leagues. He spent the entire season with Elizabethton of the Appalachian Rookie League and was 1-2 with a 4.17 ERA. He had 40 strikeouts and 13 walks in 36 2/3 innings and was the Appalachian League's Closer of the Year. He'll be assigned to Class A Clinton. A native of St. Paul, Minn., Hamburger was signed by the Twins following a tryout camp last season after he went undrafted out of junior college.
"He's a guy who has been under the radar screen," Daniels said. "He's not on all the prospect lists, but we had a couple of scouts go in and see him and they liked him. He's a big, strong kid with a fastball-slider combo. He's a guy in low-A ball, so all the normal risks apply. We'll add him to the system, bring him on and give him a chance to develop."
The Twins acquired Guardado on a waiver claim. If a trade had not been worked out in a 48-hour period, the Rangers would have pulled him back off waivers. Minnesota is responsible for the remainder of his salary and a $100,000 trade bonus.
Daniels admitted the Rangers would not have considered a deal like this if they had not fallen out of the AL Wild Card race.
"That plays into it," Daniels said. "If we were three games out, we wouldn't be in a position to trade veterans, we'd be looking to add."