April is not even over yet, but already the first pitcher has been voted off Closer Island. Manny Corpas, pack up your glove and your theme music, and make room for Brian Fuentes. Rafael Betancourt, Jon Rauch and Manny Acosta have all been shuttled into the closer's role since opening day, but in their cases, it was a closer's injury that opened the door. Fantasy owners with foresight, or at least an open slot on reserves, can take advantage of the revolving door and stash away setup relievers who have closer-like skills and a potential opportunity to steal the closer's role. For those in deeper leagues, a good setup reliever has value, even if he doesn't accumulate saves.

Which closers-in-waiting are most worth waiting for? I have ranked 10 relievers who are solid bets to perform well and position themselves for a shot at the closer's role. The rankings are based mainly on their expected contributions to ERA and WHIP, but sitting behind a shaky closer on the depth chart helps a bit, too.

10. Tony Pena, Arizona, 5.14 ERC: Pena has not been very effective in his first month, but over the course of the season, he should post better numbers than incumbent closer Brandon Lyon. A little better control and a little more luck (34% H/BIP this year) should get his ERA back under 3.00.

9. Aquilino Lopez, Detroit, 1.41 ERC: He is owned in only 5% of all leagues, but Lopez deserves roster consideration. He is putting up impressive stats, just as he did five years ago in Toronto, where he also showed he can close out games. When Todd Jones finally combusts, Lopez is as good a candidate as the Tigers have to replace him.

8. Aaron Heilman, New York Mets, 7.47 ERC: His 6.43 ERA is for real, despite whiffing 16 batters in 14 innings so far. Heilman has clogged up the bases with a 1.71 WHIP and then watched several of his baserunners score via the home run. He has shown consistently good control over the last three seasons -- better than new setup man Duaner Sanchez. It's not that anyone expects Billy Wagner to leave the closer's role anytime soon, but were something unfortunate to happen, Heilman, and not The Duaner, is the stronger candidate to fill in.

7. Pat Neshek, Minnesota, 2.00 ERC: When I wrote my original Closer Mentality column about a month ago, I received some e-mails asking why Neshek was not included on the Closers in Waiting list. Nothing against Pat, but he walked just a few too many batters to make the 3.0 K/BB ratio I was using as a cutoff. So far this year he is walking one less batter per nine innings than he did last year. Voila! His K/BB ratio to date is 3.3. Even though he won't challenge the superb Joe Nathan for the closer's job, Neshek can help a lot of Fantasy teams with Ks, ERA and WHIP.

6. Heath Bell, San Diego, 2.44 ERC: Trevor Hoffman has pitched only 8 2/3 innings so far. However, combined with his weak finish last year, his 0-2 record and 7.27 ERA and it looks like trouble. Maybe it's time for "Hell's Bells" to give way to Heath Bell. The Pads' setup man is in something of a strikeout drought this year, but over the last couple of seasons, Bell's strikeout totals have been more Hoffman-like than Hoffman's.

5. Justin Miller, Florida, 2.05 ERC: Ironically, the Marlins' tattoo magnet probably gets less ink than anyone else on this list. Toiling in South Florida obscurity, Miller is owned in just two percent of all leagues, despite putting up some of the best numbers of any non-closer over the last 12 months. Does anyone north of Lake Okeechobee know that Miller has 87 Ks in 76 innings since last season? Now they do. He has also yielded just five homers during that same span. Kevin Gregg's grip on the closer's job isn't as strong as, say, something you might see on those denture adhesive ads, so Miller may eventually provide more than just Ks, ERA and WHIP.

4. Hideki Okajima, Boston, 2.19 ERC: Sure, he has great K/9 and BB/9 rates since coming over from Japan, but Okajima's 0.96 ERA can't be for real. Hardly any of the men he leaves on base ever score, because some guy named Papelbon always cleans up his "messes." Then again, I guess that Papelbon fellow is pretty reliable. Nevermind.

3. Jonathan Broxton, Los Angeles Dodgers, 2.34 ERC: Mark Hendrickson, Livan Hernandez, Tom Glavine, Matt Chico. These were just some of the starting pitchers who recorded fewer strikeouts than Broxton last year. Add in projections for an ERA in the mid-2.00s and a WHIP under 1.20, and no wonder why he is already in nearly half of all Fantasy leagues.

2. Joba Chamberlain, New York Yankees, 1.92 ERC: If Hank Steinbrenner had his way, Chamberlain wouldn't even be on this list. For now, though, we're stuck with Joba and his ridiculous 5.2 K/BB ratio since last August. Whether his long-term future is as a starter, closer or setup guy, there doesn't seem to be much downside here. The only potential concern is that Chamberlain has only 15 starts in professional baseball, all of them in the minors, and just eight occurring above Class A.

1. Carlos Marmol, Chicago Cubs, 1.27 ERC: Marmol is similar to Broxton in his K/9 and BB/9 rates, which is obviously a great place to start. When you factor in that he gives up fewer home runs and has a better shot at possibly closing some time this year (he already has two saves), it's hard not to find a spot for this guy on your roster. In fact, owners in 58% of all leagues already agree with me.

Finally, what are Manny Corpas' owners to do now that he has gone from closer to closer-in-waiting? His April numbers are completely out of line with anything he has done in his professional career. Meanwhile, Fuentes will ring up more strikeouts, but his ERA won't likely surpass Corpas' 3.03 career mark. Corpas' statistical profile is a lot like Tony Pena's, so he is on the fringes of this list. Keeping Corpas is a reasonable use of a reserve slot. However, if you have a chance to acquire one of these 10 non-closers, they would be an upgrade over Corpas.

Glossary
Runs Created per 27 Outs (RC/27) -- An estimate of how many runs a lineup would produce per 27 outs if a particular player occupied each spot in the order; ex. the RC/27 for Miguel Cabrera would predict the productivity of a lineup where Cabrera (or his statistical equal) batted in all nine spots; created by Bill James
Component ERA (ERC) -- An estimate of a what a pitcher's ERA would be if it were based solely on actual pitching performance; created by Bill James
Base Hits per Balls in Play (H/BIP) -- The percentage of balls in play (at bats minus strikeouts and home runs) that are base hits; research by Voros McCracken and others has established that this rate is largely random and has a norm of approximately 30%
Isolated Power -- The difference between slugging percentage and batting average; created by Branch Rickey and Allan Roth
Walk Rate -- Walks / (at bats + walks)
Whiff Rate -- Strikeouts / at bats

Al Melchior was recently a Fantasy columnist and data analyst for Baseball HQ and will be providing advice columns for CBSSports.com. Click here to send him a question. Please put "Melchior" in the subject field.