– Ervin Santana was signed by the Twins last winter to help them end years of losing and spark a resurgence in the American League Central.

Now he can’t do any of that until July.

Santana, who was to earn $55 million over the next four seasons, was suspended for 80 games Friday for violating Major League Baseball’s drug prevention and treatment program. The earliest he can return to action is July 4, when the Twins visit the Kansas City Royals. Scheduled to earn $13.5 million this year as part of the richest free-agent deal in club history, Santana will not be paid during the suspension, costing him more than $6.6 million.

Mike Pelfrey, sent to the bullpen last week, will take Santana’s No. 2 spot in the rotation instead. Lefthander Aaron Thompson was recalled to replace Pelfrey.

The suspension comes at a difficult time for the Twins, who had felt good about their starting rotation as the team prepared to leave Florida and head north to open the regular season on Monday.

And it is one big ball of adversity dropped into first-year manager Paul Molitor’s lap before he manages a game.

“It’s disappointing news,” Molitor said. “But the bottom line is that I’m going to have 25 men to work with here. And as of [Friday], it’s going to be a different 25 men than it was [Thursday]. We’re going to focus on trying to compete with the people we have here.”

Santana, 32, issued a statement apologizing for the suspension but insisting that he doesn’t know how the anabolic steroid Stanozolol wound up in his body.

“I am very disappointed that I tested positive for a performance-enhancing drug,” he said. “I am frustrated that I can’t pinpoint how the substance in question entered my body. … What I can guarantee is I never knowingly took anything illegal to enhance my performance. That’s just not me, never has been and never will.”

Stanozolol, which is believed to assist in muscle growth, is one of the 74 performance-enhancing drugs (PED) that are specifically banned by the league. Its most famous user was Canadian sprinter Ben Johnson, who forfeited his gold medal in the 100 meters at the 1988 Olympics after a positive test. In baseball, Rafael Palmeiro tested positive for it in 2005.

It is not known when Santana failed the test. According to the policy, a random set of 350 players is tested during the offseason, but all players are tested upon reporting to spring training.

A year ago this week, MLB and the MLB Players Association agreed to toughen penalties for PED use, from 50 games to 80 for a first offense. A second offense triggers a 162-game suspension, and a lifetime ban is imposed for a third offense.

The penalties were toughened in the wake of a 2013 scandal involving Alex Rodriguez and other major leaguers.

The Twins weren’t sure on Friday where Santana will serve his suspension — if he will stay in Florida or spend time at his home in the Dominican Republic. If Santana agrees to it, he can serve a 16-game minor league assignment immediately preceding his reinstatement.

Twins General Manager Terry Ryan was on a field Friday in Fort Myers when he received the day- and season-altering phone call.

“It’s disappointing and difficult,” Ryan said. “We had a fairly decent spring. Now we’ve got to regroup a little bit. Hopefully it won’t affect us as we move forward.”

Molitor addressed the team in the clubhouse at Hammond Stadium before players took a bus to JetBlue Park to play Boston on Friday night.

Over the past two seasons, the Twins have tried to improve one of baseball’s worst starting rotations. Last season they brought in righthander Ricky Nolasco for four years and $49 million, plus Pelfrey for $11 million.

Nolasco went 6-12, Pelfrey spent most of the season on the disabled list, and the Twins went 70-92 — their fourth straight season of at least 92 losses.

Undaunted — and still desperate for better pitching — the Twins hit the free-agent market again last offseason to sign Santana.

Twins forced to adjust

From San Cristobal, Dominican Republic, Santana has spent 10 years in the majors, eight with the Angels and one each with the Royals and Braves. He has a career 114-100 record, 4.17 ERA, was an All-Star in 2008 and threw a no-hitter on July 27, 2011. Last year, after receiving no multiyear offers, he signed a one-year, $14.1 million contract with the Braves and went 14-10 with a 3.95 ERA.

Then came the payday with the Twins.

And now the Twins won’t see any payoff until July.

Santana’s $13.5 million contract means he earns $73,770 per day of the major league season. By July 4, he will have forfeited $6,639,300.

“I’m not sure anybody could foresee something of this nature coming down,” Ryan said.

Things like this don’t happen to the Twins, who have a squeaky-clean reputation. The only other Twins player to serve a drug suspension was reliever Juan Rincon, suspended for 10 days in May 2005 after he tested positive for an undisclosed PED. Rincon, who claimed he took fat burners, returned to the Twins and pitched two more seasons.

Rincon, by coincidence, stopped by the Twins clubhouse on Thursday to visit Torii Hunter and other former teammates.

On the field, the Twins will move on with righthander Pelfrey replacing Santana in the starting rotation. Pelfrey pitched well this spring, posting a 1.32 ERA. He will start on April 12 against the White Sox in Chicago. Nolasco moves up to the No. 2 spot behind Hughes and will pitch the Twins’ home opener — an honor that had originally been Santana’s — on April 13. Pelfrey, righthander Kyle Gibson and lefthander Tommy Milone are the rest of the starting rotation.

In the clubhouse, Molitor said the Twins’ standards haven’t changed with Santana’s suspension. Good teams improvise and move on, and that’s what he wants his club to do.

“I don’t think you really try to anticipate the various things that can happen,” Molitor said. “You deal with them when they do happen. I’m kind of a realist that way. One thing that players know is that adversity is a huge part of our game. This is obviously something that no one saw coming. I just tried to assure them that I believe in the group we have and we will deal with it the best we possibly can. It doesn’t change how I expect us to compete.”