Those two will both be breaking camp as Major League starters for the first time, along with veterans Felix Hernandez, Jason Vargas and Kevin Millwood.
Beavan, 23, started 15 games after a midseason promotion last year for Seattle. Noesi, 25, made two spot starts last year for the Yankees, but was primarily a reliever in his rookie season.
"It was good to hear that," Noesi said after learning he'd won a spot. "I've been waiting for that since whenever I started in baseball, to start in the big leagues."
Although he was with the Yankees last season, Noesi is eager to take a larger role in Seattle.
"It's big," he said. "I have just one year of playing in the big leagues. I'd like to be part of the team. I just have to keep me in there now."
Noesi will pitch the first exhibition game in Japan against the Hanshin Tigers on Sunday, while Beavan will be held in reserve in case something should happen to Felix Hernandez or Jason Vargas prior to the March 28-29 regular-season openers against the A's in the Tokyo Dome.
Beavan said it was a relief to win a job after all the competition that emerged for the rotation with the trade for Noesi and signings of Millwood and Hisashi Iwakuma.
"It's pretty hard for a rookie to look around and see everybody they signed and still think you have a shot," he said, "but being as competitive as I am, I never let anything try to get to me too much and I tried to stick to what I do and just come to camp ready to throw strikes and keep the ball down."
He succeeded with both and now has a starting role, though he and Noesi won't likely pitch in a regular-season game until the April 9-12 road trip to Texas.