Yu Darvish’s long-awaited season debut is happening.

Darvish will start Monday in the Padres’ series opener against the Diamondbacks at Petco Park after a careful comeback from an elbow issue that sidelined him in mid-March.

“We always have an open day on the schedule for Yu Darvish to start,” Padres manager Mike Shildt said Sunday afternoon. “So we’re excited to have that happen.”

Darvish, who will turn 39 in August, pitched in simulated games against minor-league hitters twice in the past 12 days. After throwing 64 pitches in his latest sim game and coming out feeling good, Darvish and the Padres decided he was ready to give them five or more innings in a big-league game.

The Padres relied on Darvish to direct his rehabilitation process from the start, trusting he knew his arm and body best after two decades as a professional pitcher between Japan and MLB.

The team maintained since the offseason that Darvish being healthy at the end of the season and in the playoffs was its No.1 aim. Darvish missed time with elbow issues each of his first four seasons with the Padres, who he joined via trade in December 2020.

After sitting out 3½ months in the middle of last season due to an elbow injury and then a personal matter, Darvish returned last September. In his final six starts — four in the regular season and two in the playoffs — Darvish posted a 2.48 ERA over 36⅓ innings. He held the Dodgers to a run on three hits in seven innings in Game 2 of the National League Division Series and allowed two runs on three hits in 6⅔ innings in Game 5.

Darvish made made a rehab start on May 14, and the Padres thought he might return after that. He hit 97 mph with his fastball that night. But Darvish felt tightness in his elbow and said he did not feel comfortable coming back.

He has worked with the Padres to alter his throwing and workout programs and has talked about the possibility of not throwing as hard in games.