FORT MYERS, Fla. — If the Minnesota Twins are going to rebound from a 2016 season marked by a club-record 103 losses, they need their youngest starting pitchers to take the next step in their progression this spring.

Jose Berrios and Tyler Duffey were among the first players in the clubhouse on Tuesday, the reporting day for Twins pitchers and catchers. As the only two under-29 returning members of the rotation, their continued development will be vital toward improvement for starting staff that had a major league-worst 5.39 ERA last year. That was almost 2½ runs higher than the World Series champion Chicago Cubs.

“At some point the young guys are going to have to step up,” Twins manager Paul Molitor said.

The 22-year-old Berrios has the highest expectations. The 32nd overall pick in the 2012 amateur draft struggled badly as a rookie, going 3-7 with an 8.02 ERA in 14 starts. He walked 35 batters and allowed 12 home runs in just 58 1-3 innings. He acknowledged that after tearing through the minor leagues, the jump to the mound at Target Field was a bit daunting.

“It was different playing in front of big crowds and a lot of fans. It was a big adjustment,” Berrios said. “I learned a lot. I learned that you have to have confidence when you go out there to pitch. This year I feel more comfortable and more confident.”

Berrios, who will miss part of camp to pitch for Puerto Rico in the World Baseball Classic, said he focused on his core muscles this offseason to improve his agility on the mound and help him maintain his velocity in later innings. Opposing hitters batted .368 off Berrios in the fifth inning or later.

“I really concentrated on my legs, my ankles, everything so that I could be better with mobility,” Berrios said. “Hopefully I can improve consistency this year.”

Duffey, who has been a teammate of Berrios at every professional level since being taken in the same 2012 draft (fifth round), also needs a bounce back from a poor 2016 in order to keep his spot in the rotation. Duffey, who had a strong rookie year (going 5-1 with a 3.10 ERA in 10 starts in 2015), took a step backward last season. The 26-year-old went 9-12 with a 6.43 ERA. Like Berrios, he was vulnerable to the long ball, giving up 25 home runs in 133 innings.

Duffey and Berrios are both part of a crowded competition at the back end of the rotation this spring that is wide open behind last year’s opening day starter, Ervin Santana and late-season acquisition, Hector Santiago.

Returning starters Kyle Gibson and Phil Hughes, who is coming back from season-ending surgery that required removal of a rib to address a shoulder injury, will be given opportunities to reclaim their spot in the rotation. That leaves Berrios and Duffey in the mix with non-roster invitees Ryan Vogelsong and Nick Tepesch and Trevor May making the transition back from the bullpen.