We had some success two weeks ago by pointing to J.P. Howell as a guy who deserved a promotion. Since that time, J.P. Howell has gotten four save opportunities. Yesterday, he struck out  Christian Guzman, Anderson Hernandez, and Nick Johnson in the 9th to pick up his third save of the season. Notably, Guzman and Johnson are two of the tougher batters in baseball to strike out.

Who are some other under-the-radar middle relievers who deserve roster consideration?

• Kiko Calero: It’s true that he’s probably not the next in line. That honor probably belongs to Leo Nunez, who has performed well this season too. Calero has been Florida’s best reliever, however. So far, Calero has whiffed 39 batters and only walked 14 in 31 innings. The Marlins pitcher was once one of the reliable relievers in baseball and a future closer candidate until injuries derailed him. Calero seems to have recovered and sports a devastating slider.
• Mark DiFelice: Coming into the season, DiFelice was a minor league journeyman whose 10 years of minor league service before a call-up in the second half last year made a pretty feel-good story. Along the way in the minors, DiFelice seemed to figure out how to strike people out while showing excellent command. He was actually on the LIMA radar heading into 2009. Much like Calero, he may not be the first in line, but with a 1.09 ERA and a 0.85 WHIP, he could factor into save opportunities later this year. Trevor Hoffman is having an amazing comeback season, but at 41 years old, anything could happen.
• Matt Thornton: We’ve been singing his praises a while, and it’s almost clear by now that Thornton is the best reliever in the White Sox bullpen. Currently, Thornton is averaging more than 12 1/2 strikeouts per nine innings and has only walked nine batters in 24 innings. Bobby Jenks is getting the job done, but it makes a great deal of sense for an out-of-contention White Sox to trade him. The second that happens, fantasy leagues will be rushing to grab Thornton, Scott Linebrink, and Octavio Dotel, but the White Sox will probably want to go with their future in Thornton.
• Greg Burke: Having only pitched 14.3 innings in the majors so far, it might be a tad early to declare Burke a closer-in-waiting. Plus, he’s setting up Heath Bell, who may be one of the three best closers in the game at the moment. Still, Burke started the season tearing up the minors and has been just as effective in San Diego. The Padres lost Jake Peavy as a trade chip, and Bell may represent the franchise’s best hopes of getting great prospects to build for the future.
• Nick Masset: We’ve been on record as predicting the flame-out of Francisco Cordero in Cincinnati for some time now.  CoCo has 15 saves and a 2.0 ERA and has been making us look a bit foolish. Still, we’re sticking to our guns, and thinking that Francisco Cordero’s time for doom is coming. It’s hard to say who would step up, but Masset is making some noise with an ERA and WHIP both sitting at or near 0.7. Masset was a decent starting pitching prospect, and often decent starting pitching prospects turn into awesome closers. (See Andrew Bailey in Oakland.) Masset has only accrued one hold on the season so far, but that stat could be a bit deceiving since only Cordero and David Weathers have entered the game in higher leverage situations.

Others to consider: Mike Wuertz, Kyle Farnsworth, Darren O’Day, Kelvim Escobar, Angel Guzman, Sergio Romo, Manny Corpas

Super long-shots: Jason Bulger, Juan Guttierez, Ronald Belisario, Dan Meyer, Clay Zavada