Kiel, a 21-year-old left-hander, signed his National Letter of Intent to play at the University of Missouri last November. Reached by phone Saturday, he said he was ready for a change of course.
"One-hundred percent, I'm signing with the Mariners," he said. "I'm going to meet with them Monday or Tuesday and get all the paperwork filled out and sign everything."
Kiel was watching his brother's baseball game Saturday when the Mariners drafted him. He didn't find out the news until he got a call from Mariners scout Joe Ross, who covers the Northwest.
"I went home and I was making food and all of a sudden, I got a call from Joe, and he was like, 'Congratulations,'' Kiel recalled. "I didn't know what it was. I didn't put two and two together. He said, 'We just picked you.'"
"I was like, 'No way!'"
At 5-foot-11 and 205 pounds, Kiel doesn't quite have the stature of one of his all-time favorite Mariners.
"I loved watching Randy Johnson when I was a kid, even though he was about a foot taller than me," he said.
But his numbers this season at Bellevue were "Big Unit"-esque. Kiel posted a 1.81 ERA and threw five complete games in 12 starts. He fanned 95 batters in 74 1/3 innings en route to a 7-4 record.
"I've been working my tail off to get to this point, and to be drafted by a team whose pro field is 10 minutes away from my house is pretty sweet," he said. "I love the stadium, just everything about it. It's surreal."
After he signs, Kiel said he'll likely begin his professional career with the Everett Aquasox, the Mariners' Short Season Class A affiliate. Their season begins next week.
Kiel said he throws a fastball that stays around 90 miles per hour, a curveball he calls a "really good pitch," a slider and a change-up.
The Mariners have scouted him since he was in high school.
"I know they initially liked me because I'm able to repeat the breaking ball and throw the offspeed stuff for strikes consistently," he said. "That's what they like, especially at the next level, to be able to throw not just fastballs, but secondary pitches as well."