Justin Masterson’s body never gave him a chance to compete last year.

Betrayed by injuries to his knee, shoulder and oblique, Masterson made it clear Friday that whatever ailed him in 2014, he doesn’t expect it to be an issue next season.

Introduced on a conference call after signing a one-year deal, Masterson is anxious to prove last season (7-9, 5.88 ERA) was a fluke.

“Last year was purely health,” Masterson said. “We tried to make corrections through mechanical type things, because I wasn’t experiencing any pain, but I lost some flexibility and quite honestly a lot of other things. I’m 100 percent confident we’ll be good to go. … I have confidence this will probably be one of the best seasons I’ve ever had.”

Masterson traces his issues to an oblique strain at the end of 2013, his best season as a pro, that never properly healed. That produced issues in his body rotation through his delivery, which in turn shaved three miles per hour off his fastball, down to roughly 90 mph.

“When I tore my oblique at the end of 2013, I had a lot of scar tissue I didn’t necessarily work through and that led to a lot of the issues,” Masterson said.

“We’ve been able to loosen that up and get some of my rotation back. I think that’s going to be one of the driving factors to get that velocity back so I can be just as effective as I have been.”

The Red Sox would love to get the Masterson of 2013, an All-Star who won 14 games with a 3.45 ERA. Masterson is just happy to be back with the Red Sox, the organization that selected him in the second round of the 2006 draft.

He debuted in 2008 – pitching well in the playoffs – and looked like a piece of the future until being traded to the Indians for catcher Victor Martinez at the 2009 trade deadline.

“It was definitely difficult at the time,” Masterson said. “In my mind I was thinking, ‘This is great, things are working out well, I’ll probably be here for a while.’ It didn’t happen. I got shipped away, for good reasoning, but had a great opportunity to really re-establish myself as a starting pitcher. So although it was difficult in the end, it provided a lot of great things.”

And now things have come full circle for Masterson, who also received an offer from the Rangers. “At the time, I was like, ‘It would be cool to be back in Boston at some time,’ ” he said.

“And here we are.”

NATIONALS: General Manager Mike Rizzo said that club was “disappointed” that outfielder Bryce Harper did not show up Saturday at the NatsFest fan festival.

In an email issued through his agent’s office, Harper said: “I have attended NatsFest each year and always enjoy my experience with the fans, but was unable to attend this year’s event due to matters out of my control. I look forward to next year’s NatsFest.”

The Major League Baseball Players Association has filed a grievance on Harper’s behalf over whether he should able to void the 2015 terms in the final season of a $9.9 million, five-year contract he signed when drafted. An arbitrator hearing could happen next week if the case isn’t settled.

“We’re disappointed he’s not here, but he chose not to be here because of the grievance,” Rizzo said. The GM said he couldn’t discuss the grievance because it’s “a legal matter.”

n Starting pitchers Jordan Zimmermann and Doug Fister aren’t paying attention to speculation about whether they’ll be traded before next season, the last of their current contracts with Washington.

Shortstop Ian Desmond also could be bound for free agency a year from now – or sent to another team before that – and acknowledges he’s well aware he could end up leaving the franchise that drafted him out of high school in 2004.

“I’ve got guys that I consider ‘Dad’ in this organization. I’ve got guys that are just like my brothers,” Desmond said Saturday at the club’s fan festival. “I was 18 when I signed; I had like four armpit hairs. Now I’ve got three kids.”

Asked if he found recent trade talk jarring, Desmond replied: ” ‘Jarring’? Look, this isn’t my first day on the job. I understand what’s going on. … It’s part of the business. The Nationals didn’t get here by sitting still.”

What has been a relatively quiet offseason for Washington could become drastically different in the coming months, depending on what happens with a group of key players who aren’t signed beyond 2015.

In addition to Desmond (the team’s top returning player in homers, 24, and RBI, 91), Zimmermann (14-5, 2.66 ERA, no-hitter in the regular-season finale) and Fister (club-high 16 wins, rotation-leading 2.41 ERA), that category includes setup man Tyler Clippard and leadoff hitter Denard Span.

GM Mike Rizzo might trade one or more.

Or he could try as much as possible to keep together a club that won the NL East title two of the past three seasons.

“If it’s a fair value (offer) … I would gladly sign,” said Zimmermann. “But at the end of the day, it’s got to be something that’s fair. And if it’s not, then I’ll be moving on.”