Nationals left-hander Gio Gonzalez was cleared by Major League Baseball in the Biogenesis case on Monday. (Toni L. Sandys/THE WASHINGTON POST)

After he reported to spring training in Viera, Fla., six months ago, Washington Nationals starting pitcher Gio Gonzalez stood before reporters in the dugout and declared his innocence. “I’ve never taken performance-enhancing drugs, and I never will,” Gonzalez said about his alleged tie to Biogenesis, a now-defunct anti-aging clinic that distributed banned substances to players. The Nationals brass, his teammates and the players’ union supported and believed him.

On Monday, Major League Baseball announced sweeping and unprecedented 50-game suspensions for 12 players for drug violations, in addition to a 211-game ban for Alex Rodriguez. Despite being originally linked to that South Florida clinic, Gonzalez was not among the disciplined players. MLB’s investigation found “no violations of the Joint Drug Prevention and Treatment Program” by Gonzalez.

“I am very pleased that Major League Baseball has cleared my name,” Gonzalez said in a statement released by the Nationals. “With this process now complete, I have no lingering sense of animosity, as I quickly realized that the objective of this investigation was to clean up our game. This is an ideal that I share with both Major League Baseball and the MLBPA. I would also like to acknowledge the unwavering support of my teammates, the Lerner Family, Mike Rizzo, Davey Johnson, our coaching staff and Nationals fans everywhere.”

In the sport’s largest crackdown on drug use, MLB announced the suspensions after an aggressive investigation into Biogenesis and clinic chief Anthony Bosch. A January report by the Miami New Times originally tied Gonzalez — among other players, like Rodriguez, Jhonny Peralta, Everth Cabrera, Melky Cabrera and Nelson Cruz — to Biogenesis.

Ryan Braun was later linked to the clinic by a Yahoo report, and he accepted a 65-game suspension two weeks ago. Rodriguez has been banned through the 2014 season and is appealing his suspension. Without positive drug tests, MLB investigators gathered evidence to build a case against players, including reported cooperation from Bosch and an associate.

Gonzalez and Danny Valencia of the Baltimore Orioles were the only players found to have committed no violations. Melky Cabrera of the Toronto Blue Jays, Bartolo Colon of the Oakland Athletics and Yasmani Grandal of the San Diego Padres, who already served 50-game suspensions for positive drug tests, avoided further discipline.

“Their names came up in Biogenesis,” Michael Weiner, executive director of the MLBPA, said of Gonzalez and Valencia. “That’s really about all I can say. It was determined that they didn’t use performance-enhancing substances, that they didn’t possess performance-enhancing substances and that they were — in the end, they weren’t disciplined.”

MLB investigators did not find any evidence that Gonzalez ever received a banned substance, according to a person familiar with the investigation. A separate person with knowledge of the situation said league officials found Gonzalez may have been targeted as a potential client by Biogenesis but concluded that the pitcher wasn’t a client. Many of the players linked to the clinic had ties to the Miami area, including Gonzalez, a native of nearby Hialeah, Fla.

Gonzalez, 27, a two-time all-star, is represented by ACES, the agency that has come under fire from MLB for having a handful of its clients tied to Biogenesis. His clearing is welcome news for the Nationals, who are battling for a playoff spot and whose starting rotation has been depleted by injuries and uneven performances. Gonzalez is scheduled to take the mound at Nationals Park on Tuesday in a crucial game against the division rival Atlanta Braves.

Gonzalez was first tied to the clinic and to various substances, including “Zinc/MIC . . . and Aminorip” and a testosterone-laden “pink cream,” by the New Times report. Gonzalez, however, forcefully maintained he didn’t have any contact with Bosch or the clinic. Gonzalez said in February he was “shocked” by the New Times report and that it was his father, Max, who was the client of Biogenesis for weight-loss medicine.

“Gio’s a good guy and obviously wasn’t cheating,” reliever Tyler Clippard said. “So for him to be on the list in the first place was kind of unfortunate, but I guess it’s obviously good for him to kind of get a clean slate.”

Gonzalez has pitched solidly through the cloud of the investigation. As a key cog in the team’s top trio of starters, the left-hander has posted a a 7-4 record and 3.57 ERA over 1332 / 3 innings. He maintained his outgoing personality in the clubhouse, but some close to him acknowledged the allegations weighed on him.

“He handled it well,” General Manager Mike Rizzo said. “It’s a testament to his mental makeup and the way he prepares for games. I thought he’s thrown extremely well considering.”

Beyond his statement, Gonzalez wasn’t made available to reporters Monday. His father declined to comment Monday.

Rizzo and Manager Davey Johnson both spoke with Gonzalez after the allegations first surfaced and their conversations put both men at ease. They have both publicly backed Gonzalez since then.

“I believed him from the get-go,” Johnson said. “I understood the whole thing. I wish MLB would have cleared it up a long time ago. It would have been easier on him. But he’s handled it very well.”