The Detroit Tigers have whittled their bullpen (in terms of reliability) down to four pitchers setting up closer Joakim Soria—Alex Wilson, Blaine Hardy,  Al Alburquerque and Neftali Feliz.

The rest have been maddeningly inconsistent. Bruce Rondon and Ian Krol seem like long-term pieces, however both have abnormally high ERAs (in albeit small sample sizes). Rondon’s is 9.35 in 8.2 innings while Krol’s is 6.14 in 14.2 innings.

If the Feliz’ arrival has shown the Tigers anything, it’s that quality relief options are available—and they may just need a change of scenery to thrive. Here are some low-buy trade targets the Tigers could look into in order to bolster the team’s bullpen.

(RELATED: Neftali Feliz Signing a Smart Move by the Tigers)

Steve Cishek, Miami Marlins

Per the Boston Globe’s Nick Cafardo, the Tigers have been watching Steve Cishek. This makes sense.

Tweet #Whiff & tag @Marlins when our pitchers record Ks! Tweets help @headshoulders donate to local @MLBRBI programs. pic.twitter.com/47OJqOb554

— Miami Marlins (@Marlins) July 21, 2015

Cishek struggled mightily to start the year, so much so that he was sent down to Double-A to work things out. The former closer is back with the big league club, and seems to have figured things out. As a setup reliever since June 14^th, Cishek has a 0.93 ERA and nine strikeouts in 9.2 innings.

The most unnecessary luxury on a losing team is a good reliever, so if Miami sells off pieces, Cishek may be out the door. He’s even more expandable considering how well A.J. Ramos has fared as a closer (1.55 ERA, 14 saves). This isn’t even to mention the presences of Sam Dyson (3.48 ERA), Bryan Morris (3.31) and Carter Capps (1.55).

It seems that the Tigers like to acquire relievers with closing experience to serve in a non-closer role. This has happened with everyone from Jim Johnson and Joel Hanrahan to Joakim Soria and Feliz. Cishek (94 careers saves) would fit the mold.

Addison Reed, Arizona Diamondbacks

Yet another former closer who’s had troubles, former White Sox reliever Addison Reed would be the ultimate low-buy for the Tigers.

Reed has a career 4.39 ERA, including a 5.92 number this year, but when you look at the numbers more closely, he comes off as a much better pitcher. The former closer’s FIP is a much-more-acceptable 3.84 this year. In other words, the Diamondbacks aren’t doing him any favors defensively.

Over the course of a year-and-a-half in the desert, Reed has nine losses and 35 saves (only three this season). His ERA in Arizona is 4.73. Going purely on those numbers alone, the D-Backs may be inclined to move him, especially considering the team’s depth chart.

Arizona is stocked with quality relievers, from closer Brad Ziegler to setup relievers Andrew Chafin (2.90 ERA), to Randall Delgado (2.93 ERA) and the duo of Daniel Hudson and Oliver Perez (3.32 and 3.46 respectively).

Reed isn’t even on the team’s big league roster. They’d probably be more than open to moving him, especially given his salary. Nonetheless, he’d be a good low-buy option for the Tigers, especially with his closing expertise (104 career saves).

Joe Thatcher, (Formerly of the) Houston Astros

Finally! A non-closer. Joe Thatcher was just designated for assignment by the Astros and is available. Not only is Thatcher wildly non-expensive, relative to his value, he’s also been consistent for Houston.

Thatcher has a respectable 3.79 ERA and an even more attractive 3.17 FIP. The former Angel has struggled of late (27.00 ERA in last five appearances, spanning 1.1 innings), but was dynamite before that. In 31 appearances prior to the struggles, Thatcher posted a sparkling 2.04 ERA.

Given his relative inexpensiveness and success, the Tigers should take a flier on Thatcher. His arrival would be another step towards having a strong bullpen.

Jean Machi, (Formerly of the) San Francisco Giants

It seems that the piece has now moved from struggling former closers to relievers that were recently designated for assignment. Joining Thatcher in the DFA category is now former Giants’ reliever Jean Machi.

Machi excelled in 2014 and 2014 for the Giants, posting a spectacular 2.49 ERA and a 2.93 FIP in 119.1 innings. He struck out 102 batters over that span while accumulating 10 wins. The four-year veteran would likely pitch earlier in games, a la Hardy, and would provide yet another dependable reliever in the Tigers’ bullpen.

Machi does have a 5.14 ERA this year, but his 4.20 FIP suggests he’s better than his high ERA. Despite those “struggles,” the right-handed pitcher has been filthy against lefties this year. Left-handed hitters have produced a miniscule .120 batting average against Machi. Other nasty numbers? Left-handed batters have posted a .241 OBP and a .160 slugging percentage. That’s good for a .401 OPS against. Those are p-r-e-t-t-y good numbers for someone on the waiver wire.

Since he’s been designated for assignment, the Tigers won’t have to pay much to acquire him. Which is nice when you don’t have a boatload of assets to trade.

All stats courtesy of Baseball-Reference.com unless otherwise noted.

For more Tigers, click here. For more baseball, click here.