Balfour is the Rays closer. I agree, they need one more arm. Here are the list of high end guys who will either break camp or be making their debuts in the pen.
1. Dellin Betances- the guy's big league debut was a disaster. He then had 3 solid appearances before being the guy who pitched before Mariano in his final game. He then lit up the stros 3 days later. The kid has a serious arm. Mid to high 90s, knockout breaking ball. His lack of development of his change cost him his starting career as well as his command. Before being called up, he had a 1.35ERA as a reliever in 32 games with 83K's in 60IP with a BAA of .163. He has ace level stuff and I have a feeling he plays a big role, good or bad, in our 2014 pen.
2. Mark Montgomery- Mark had a bad 2013 by his standards. In 2012, he was topping out in the mid 90s on his way to striking out 99 batters in 64IP. That isn't a typo. Last yr, he dealt with some elbow tendinitis and came back with less velocity, which led to him striking out a measly 10 batters per inning. He says he's healthy, and if he gets his fastball back, he has a chance to be in the back end of the pen early on. He has the nastiest slider in the minor leagues after all.
3. Chase Whitley- another guy who gets overlooked because he doesn't have blowaway stuff, but he can top out around 96 with a solid 4 pitch arsenal. He started 5 games last yr and still ended up striking out nearly a batter an inning. He'll be on the short list early on
4. Jose Ramirez- this guy was a rotation candidate out of ST last yr, then got hurt and didn't garner the same attention after that. Right now, he's squarely behind Banuelos, Pineda, Phelps, Warren and Nuno for the 5th starter spot, and with his stuff, he could make it to the bigs this yr as a reliever. He throws high 90s, has a lights out changeup and a good slider. His control has been at issue, so who knows what will happen if he comes through in the pen
5. Francisco Rondon- there is a reason he is on the 40 man with god awful minor league stats. He's a lefty with mid to high 90s cheese and a knockout slider. His changeup sucks and he has serious issues with his command, which has led to him failing as a starter. He was promoted to SWB where he was to relieve. He is likely behind Cabral and Thornton, but he is the next lefty to come up.
There are plenty more. Tommy Kahnle was selected in the Rule V, but is unlikely to stick. He throws mid 90s with a solid slider with some command issues. Danny Burawa tops out at 101mph. There are tons of these guys. I think a few, especially Betances and Montgomery, should play a prominent role in the pen come 2014. Like I have said before, the only minor league area where we are truly stocked is the bullpen.