AaronGleeman.com

After missing out on LaTroy Hawkins last month the Twins decided to bring back another key member of the 2003 bullpen yesterday afternoon, acquiring Eddie Guardado from the Rangers for 21-year-old pitching prospect Mark Hamburger. Like Hawkins, Guardado left the Twins as a free agent following the 2003 season, signing a three-year, $13 million contract with the Mariners while the Twins selected Glen Perkins with one of the draft picks they received as compensation for letting him walk.

While Joe Nathan thrived as his replacement with the Twins, Guardado spent two seasons closing for a last-place team in Seattle before being stripped of ninth-inning duties midway through his third year. He converted 8-of-9 saves for the Reds after being traded that July, but was sidelined by an elbow injury that eventually required Tommy John surgery. After sitting out a year to recover from surgery he came back in August of last season and struggled, posting a 7.24 ERA in 15 outings with the Reds.

Cut loose after the season, Guardado signed an incentive-laden one-year deal with the Rangers and resurrected his career at the age of 37. Shoulder soreness knocked him out for most of April, but once healthy he emerged as the Rangers' primary setup man and recently took over closer duties from C.J. Wilson. Despite calling one of the majors' most hitter-friendly ballparks home, Guardado posted a 3.65 ERA and 28-to-17 strikeout-to-walk ratio over 49.1 innings with the Rangers.

For the past couple months this space has been filled with pleas for the Twins to add another capable arm to the struggling bullpen, but the team didn't pull off a trade for Hawkins, misguidedly chose not to claim Chad Bradford off waivers, failed to sign Al Reyes, and inexplicably refuses to bring up Bobby Korecky from Triple-A. Age and injuries mean that Guardado is no longer the same "Everyday Eddie" who Twins fans remember, but he still has enough left in the tank to at least fit the "capable arm" bill.

How much of an upgrade he represents for the Twins' bullpen depends on how you examine his time with the Rangers. A 3.65 ERA in Texas is very solid and his .220/.286/.358 opponent's batting line is great. Beyond that, at 3.77 his Fielding Independent Pitching (FIP) ranks 30th in the AL among relievers with at least 40 innings (slightly below Jesse Crain at 3.71 and Bradford at 3.73). In other words, FIP suggests that he's pitched well enough to be the second or third option in most bullpens.

However, FIP's souped-up brother Expected Fielding Independent Pitching (xFIP) tells a different story. Guardado has a 5.25 xFIP, which is well below par for a reliever and would rank as the second-worst mark for anyone who's pitched for the Twins this season behind only Juan Rincon at 5.56. How can two seemingly similar stats differ so much in their evaluation of Guardado's performance? It's mostly due to FIP quantifying what has happened and xFIP predicting what will happen.

Much of the disagreement between the two metrics comes from Guardado's home-run rate. FIP sees that he's allowed just three homers in 49.1 innings and credits him for keeping the ball in the ballpark the same way that it credits him for recording 28 strikeouts or handing out 17 walks. On the other hand, xFIP sees that he's an extreme fly-ball pitcher and just 3.7 percent of his fly balls have gone over the fence, and predicts that rate will rise toward Guardado's career norms and the MLB average over time.

GUARDADO HR RATE
 
YEAR     HR/FB
2002     10.0%
2003      7.5%
2004     12.9%
2005      9.0%
2006     16.9%
2007      8.7%
2008      3.7%

Just 3.7 percent of his fly balls going for homers sticks out from the rest of his career like a sore thumb, which is why xFIP has the edge over FIP in terms of predictive value. Allowing 3.7 homers per 100 fly balls simply isn't likely to be sustainable over the long haul, although as the Twins' lineup has shown by continuing to thrive with runners in scoring position that doesn't mean it can't be sustained for quite a while. However, the smart money would be on Guardado serving up more homers going forward.

From 2002-2007 he allowed a homer on 10.6 percent of his fly balls (MLB average is 11 percent) while never posting a homer rate below 7.5 percent, so his current rate of 3.7 percent is pretty clearly a fluke. Despite that FIP sees Guardado's three homers allowed and asks no more questions, crediting him with keeping the ball in the ballpark. Meanwhile, xFIP looks at his extreme fly-ball rate and suggests that he's been very fortunate to give up just three homers, predicting a lot more long balls in his future.

Guardado also got excellent defensive support from the Rangers, who turned 76 percent of his balls in play into outs. Like his home-run rate, allowing a .240 average on balls in play is far better than his career norm (.288) and the MLB average (.305). Compared to his 2001-2003 peak, he's striking out 41 percent fewer batters, which makes sense given that his average fastball is now clocked at 85.9 miles per hour, down 1-2 mph from his time with the Mariners and 3-4 mph from his time with the Twins.

GUARDADO        PA      SO%     BB%      GB%
2001-2003      800     24.6     5.9     31.0
2008           194     14.4     7.7     26.0

All of which is why Guardado likely doesn't represent as much of an upgrade as his ERA suggests. Of course, even if xFIP is right and Guardado is truly closer to a 5.00 ERA pitcher than a 3.65 ERA pitcher at this point, that doesn't mean his luck will necessarily even out over the next six weeks. My preference would have been to claim Bradford off waivers or call up Korecky from Triple-A, but for whatever reason the Twins opted against those choices.

However, if the only options at this late date in the year were sticking with the current group of relievers or dealing for a familiar veteran with a somewhat lucky 3.65 ERA, then bringing back Guardado makes plenty of sense. He's not likely to have as much success as he did with the Rangers, but Guardado out-running regression to the mean for another 10-15 innings certainly wouldn't surprise me. He's a "capable arm" with tons of late-inning experience and the Twins trust him. Plus, the price was right.

Previous reports suggested that the Rangers were asking for one of the Twins' top pitching prospects in exchange for Guardado, but in the end they accepted a rookie-ball reliever who was signed after an open tryout at the Metrodome last year. Hamburger throws in the mid-90s and has been impressive at Elizabethton, posting a 40-to-13 strikeout-to-walk ratio in 36.2 innings, but the odds are heavily against the Twins being haunted by the decision to deal an undrafted rookie-ball reliever.

Beyond that, even if Guardado stays healthy and effective while making enough appearances to reach the various performance bonuses in his contract, he'll cost less than the Twins pocketed by dumping Livan Hernandez on the Rockies. As we saw last night Guardado isn't going to "fix" the bullpen all by himself and calling up Korecky from Triple-A for further help still makes all kinds of sense, but general manager Bill Smith has at least given Ron Gardenhire another decent late-inning option. Finally.

Welcome back, Eddie.