DETROIT – Outfielder Byron Buxton, ranked as the second-best prospect in baseball at the start of the season, was in the Twins' Opening Day lineup. Righthander Jose Berrios, ranked 26th overall and ninth among pitchers, debuted April 27.

Both are now down in Class AAA Rochester to work on flaws. Berrios is the most recent demotion, which happened after he gave up seven runs in two-thirds of an inning Monday in a 10-8 loss to the Tigers.

With the Twins entering Tuesday with a 10-27 record, it would seem their chances at a winning season have been dashed. So why not allow Buxton and Berrios to stay up and learn how to produce in the major leagues?

"I'm not on the bandwagon about [it's a] lost season and let's get these players some major league experience," Twins manager Paul Molitor said. "That doesn't make a lot of sense to me at this stage, and I don't think that anybody thinks that it is [all] lost. I think maybe some people on the outside do. And they could be proved to be right over time.

"I'm not going to let that kid [Berrios] keep going out there until he has a little better idea of what he's doing with the baseball. I just haven't seen it enough to make me think he is going to figure it out right now."

In four starts, Berrios was 1-1 with a 10.20 ERA. In 15 innings, he gave up 20 hits, five of them home runs, while walking 12 batters.

Buxton, who was sent down to Rochester on April 25, struggled to make contact, hit fly balls when he did and couldn't get on base to showcase his elite speed. He was batting .156 when he was sent down. He's batting .301 at Rochester, but on Tuesday missed his second consecutive game because of back spasms suffered Saturday and remains day-to-day.

Molitor was asked how the Twins weigh demoting a player vs. letting him figure things out while still in the majors.

"[You] try to determine how much failure do you want a guy to experience up here," Molitor said. "Kind of like Byron's case. I was somewhat adamant about thinking we were doing the right thing by bringing him up at the start of the year, and we ended up sending him back. It was the right thing for him, and I think it's the right thing for Jose."

And the new starter is …

The Twins announced that lefthander Pat Dean will make his first major league start Saturday against Toronto, taking Berrios' spot in the rotation.

Dean, 26, relieved Berrios in Monday's game and held the Tigers to two runs over 5⅓ innings while throwing 91 pitches.

"It was impressive," Molitor said of Dean, a third-round pick out of Boston College in 2010.

Dean will be the ninth different starter for the Twins this season.

Etc.

• The Twins called up lefthander Taylor Rogers to replace Berrios on the roster, but he will work out of the bullpen. He said he has enough stamina to throw 60-70 pitches, which makes him a good fit for long relief — or to move into the rotation if someone else falters. Rogers made seven appearances, including two starts, for Rochester, going 0-1 with a 4.50 ERA. He was with the Twins briefly last month and made one appearance, retiring two of the three batters he faced April 14 against the White Sox.

• The Twins have signed outfielder Robbie Grossman to a minor league contract and assigned him to Rochester. Grossman, 26, played in 190 games for Houston over the past three seasons, batting .240. He was batting .256 in 34 games with Class AAA Columbus of the Indians chain when he exercised an out clause in his contract. He has a June 15 out clause in his deal with the Twins, meaning he can become a free agent if not in the majors by then.