While Diamond has made progress after a bone chip was removed from his elbow in December, he will begin the season on the 15-day disabled list and is expected to start April 12 versus the visiting New York Mets, according to mlb.com.
Diamond, who hails from Guelph, Ont., will spend the final two weeks of spring training on the minor league side of Twins camp.
On Monday, the 26-year-old was scheduled to throw two innings and about 30 pitches in a Class A game, four days after throwing live batting practice for the first time since his surgery.
“It’s exciting just because I’m finally catching up or at least getting back into games. It’s a big step being able to jump back into games,” Diamond told Minnesota reporters recently at the team’s spring training camp in Fort Myers, Fla.
Diamond, who also threw 40 to 50 pitches in a bullpen session on Saturday, needs to work his way to the 90-pitch range for the regular season and that will take another three to four starts.
He emerged as the Twins ace last season, winning 12 games with a 3.54 earned-run average in 27 starts. Diamond also displayed pinpoint control with just 31 walks in 173 innings pitched.
The southpaw entered the off-season planning to add weight to his six-foot-three, 215-pound frame, hoping it would help him through the rigours of a long season in an attempt to reach 200 innings pitched.