"But as tough as that is, it is just as difficult to stay there," he said. That means doing whatever it takes to maintain that status.
When the 2012 season ended, the 27-year-old right-hander had pitched in four games for the Los Angeles Angels and had appeared in 50 Major League games overall from 2010-12. He had shoulder difficulties during Spring Training and thought he might try to stretch his arm out in winter ball in the Dominican Republic or perhaps Venezuela. But the Angels had other ideas.
Angels assistant general manager Scott Servais called Cassevah's agent and said the club wanted him to pitch in the Arizona Fall League.
The Arizona Fall League? Isn't that supposed to be for guys on their way up, not guys who have Major League experience?
"I was very surprised at first," Cassevah said. "But I think there are still some good opportunities with the Angels. They have kind of shuffled their bullpen a little. I know that I also am out of options, so coming here will give me a chance to pitch in front of scouts from other teams."
Cassevah likely remains in the Angels' bullpen plans for now, and they are having him stretch out his arm by getting more innings as a starter for the AFL's Scottsdale Scorpions.
Starting seems to agree with him, at least temporarily. He has been named the AFL's Pitcher of the Week for Week 4. In his lone start, he pitched five innings, giving up three hits and striking out five.
Entering Tuesday's start against Salt River, he was 2-0 in four starts and had an 0.56 ERA, best among the league's starters. He had allowed just one earned run in 16 innings.
Honored as the AFL's Player of the Week was Cassevah's Scottsdale teammate, Slade Heathcott of the New York Yankees.
"As long as I stay healthy, I think I have a good shot at getting a spot [in the Angels' bullpen]," Cassevah said.
Coming out of Spring Training in 2012, Cassevah found himself pitching for Inland Empire of the Class A Advanced California League (five games), then most of the rest of the season with Triple-A Salt Lake, appearing in 44 games with 10 saves. In between was a stop with the big club.
"That first month, the shoulder [soreness] affected my fastball command. I was leaving the pitches up," Cassevah said. "I need to have the fastball to work with the sinker, the slider and the split[-finger]."
There was a slight tear in his labrum. Cassevah was examined by noted Southern California orthopedist Dr. Lewis Yocum, but the tear wasn't to the point of requiring surgery. Cassevah also consulted the Angels medical staff and decided to strengthen it through rehabilitation.
"You don't want something like that to keep you from pitching if you don't have to," Cassevah said.
He was drafted in the 34th round by the Angels in 2004 and spent a brief period (about 2 1/2 weeks) during Spring Training in 2010 with the Oakland Athletics after they selected him in the Rule 5 Draft in 2009. Cassevah was later returned to the Angels.
"Unfortunately, it didn't work out, but it was good to see how another team does things," he said of his A's experience. "I'm still in a good situation."
The first year or two after being drafted was a bit difficult, being all the way across the country from his home near Pensacola, Fla.
"You're in bigger cities, and I missed my family and friends. I had a girlfriend who was going to Florida State," Cassevah said. "But you mature, get older and you learn that this is a profession, and pursue your dream."
When he first reached the Major Leagues, Cassevah admitted he was a bit nervous. The sight of manager Mike Scioscia in the clubhouse intimidated him, but he gradually began to feel more comfortable. He had the guidance of veteran relievers Scot Shields and Scott Downs.
"I would pick their brains," Cassevah said. "Shields pretty much told me that the relief role is tough. No matter where you are -- whether it's in rookie ball, Double-A or the big leagues -- that it's still 60 feet, 6 inches to the plate. He said, 'Don't let the hitters take it away from you.'"
They haven't thus far in the AFL. Whether it's starting or relieving, Cassevah is doing his best to keep them at bay.
Don Ketchum is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.