The fact he's even in this position -- after going undrafted out of college, spending two years in independent ball and navigating through pro baseball with a very limited arsenal -- is a triumph in itself.
For most of the last two years, Sisk has been a solid late-inning reliever for the Triple-A Omaha Storm Chasers of the hitter-friendly Pacific Coast League, posting a 2.18 ERA in 99 1/3 innings, but blocked by a deep, young Royals bullpen.
Five years ago, the 27-year-old southpaw almost left baseball for good.
"I was 90 percent close to just calling it quits," Sisk said. "My family practically begged me to give it one more chance."
Three years as a starter at California's Azusa Pacific University -- and an elbow injury that cost him his junior season -- led nowhere in the First-Year Player Draft. So Sisk took a year off, working a construction job with his cousin in Sacramento. Then, in the summer of 2007, Sisk gave independent ball a shot.
Not just any independent ball, though.
This was the since-defunct Continental Baseball League, in its very first year of existence, which paid players $1,000 for the entire summer, struggled to break 100 fans at games and, worst of all, hardly drew scouts.
Sisk, still out of shape and recovering, couldn't even pitch well there.
"I had a bad first year -- it was very demoralizing," Sisk said. "And there was maybe -- maybe! -- one or two scouts that came to any of the games the whole time. There was no point."
But Sisk ultimately decided he'd give it one more chance, just to see what would happen.
"If I don't do well, nothing happens, I don't get signed by anybody or get a chance with anybody, I'm done," Sisk said. "Indi ball doesn't pay very well. I can't sit here and try to make a living off this and try to get married and try to start a family and all this stuff, making what I was making. I was going to be done after my second year of indi ball. And it just so happened the Royals gave me a chance."
And for five years in the Royals' system, the 6-foot-2 Sisk successfully made the transition to the bullpen, compiling a 2.59 ERA and a 1.16 WHIP, striking out 376 batters in 340 1/3 innings, and somehow being successful against both righties and lefties.
"If you just go watch him -- like if you're a scout and you only see him throw one time -- he's not going to impress you all that much," said Doug Henry, the Royals' bullpen coach who served as pitching coach when Sisk was in Class A ball and Triple-A. "But just day in and day out, he doesn't give up any runs."
Sisk throws a solid changeup and a slider that's still a work in progress. His money pitch is a fastball that sits somewhere between 88 and 92 mph. It doesn't really have late life, and it certainly doesn't move like Ernesto Frieri's. But the combination of Sisk's delivery and the threat of his changeup makes it an awfully deceptive pitch.
It even has a nickname: The Invisi-ball.
"For some reason, hitters just don't pick it up," Henry said. "It's amazing. When I watch it over the years, I just wonder, 'How does this guy not get hit?' But he keeps going out there, striking guys out and not giving up a lot of runs."
Sisk is Texas-bred and makes his home in San Jose, Calif. He played Winter ball in Venezuela for about a month before deciding to return home last weekend, because he was tired after a long season and because he heard about this new opportunity to hopefully reach the Majors with a new team.
"I'm really stoked, actually," Sisk said of joining the Angels' organization. "It was a surprise, and I was ecstatic when I found out. I still am."
The trade made sense for both sides.
The Angels had no interest in picking up Santana's $13 million option after he posted a 5.16 ERA and gave up a Major League-leading 39 homers in 2012. So instead, they sent Santana and $1 million -- the cost of his buyout -- to a Royals team that's lacking in starting pitching and had Sisk, who is eligible to be taken in the upcoming Rule 5 Draft.
"We're going to bring him in and let him compete," Dipoto said, "That's all any player can ask for."
That's all Sisk has ever done, frankly.
"I knew going into it that I was going to have to work 10 times harder than the next guy in order to make it, just because I was a non-drafted free agent being signed out of indi ball," Sisk said. "I'm the guy at the very bottom of the ladder.
"I'm fine with that. That actually motivates me."