"You're not going to do any good worrying about it," Balfour said. "I was angry. I was upset. I told myself, 'I'm going to prove them wrong.' I got fired up. The only way I could do it was to go out on the field and show that I belonged."
Other Major League teams could have claimed Balfour at that point, but none did, and he accepted his assignment to Triple-A Durham. Balfour said it took him seven to 10 days to get the anger out of his system.
"I told myself, 'I've just got to grind it out,'" Balfour said.
And grind he did. Opposing batters hit just .029 against him as he posted a 1-0 record for the Bulls with eight saves in eight opportunities. On May 29, the Rays recalled the right-hander, and he has since appeared in 18 of the team's 40 games.
Balfour carried a 2-1 record with a 1.54 ERA into Saturday night's game, and he's pitched well enough to become the Rays' de facto closer.
"I think I'm just pitching with aggression," Balfour said. "I'm not really thinking too much, to be honest."
His role will likely change when Troy Percival (left hamstring strain) returns from the 15-day disabled list.
"You get 300-something saves, there's no question, he's the guy," Balfour said of Percival, who has closed out 343 games over a 13-year career. "If it means he's three days in a row and can't go out there the next day and I get an opportunity, that's great. If I pitch the seventh or eighth inning, that's great, too.
"I must admit, I enjoy [closing]. If I get some opportunities, that's great. I'm sure he's going to get the majority of them. And like I say, when the time comes and I get the chance to get in there, I'll take it."
When Percival returns, Balfour will likely serve as a setup man with occasional opportunities to close. Manager Joe Maddon said Balfour is the kind of pitcher who could be groomed to be the team's future closer.
"He's got that kind of stuff," Maddon said. "And the biggest thing to me is the makeup. The closer makeup -- it's different. Those last three outs of the game are different. People can argue as much as they want, but they are. And the last out of the game is always the most difficult. ... I think, from my perspective, [Balfour is] growing into that makeup where he could do that one day. Definitely his stuff is good enough."