Ross Detwiler. (Photo by Mitchell Leff/Getty Images)

Nearly two months have passed since the end of the Nationals‘ season, ample time for Ross Detwiler to reflect on his up-and-down season. He reported to Viera last spring having to compete for a spot in the starting rotation. He was moved into the bullpen during spring training. He went through spurts of effectiveness and inconsistency throughout the season, his patchy usage a big factor. And by the end of the season, he was left off the Nationals’ postseason roster against the San Francisco Giants.

“I was extremely disappointed,” said Detwiler by telephone this week from his offseason home near St. Louis, making his first comments about not making the playoff roster. “I know it was a team full of lefties and I thought matchup-wise we would have gone with three lefties if we were trying to match up. I guess they had a different plan. Maybe someone had a better history than me and it came down to two people. I don’t know. I know down the stretch I hadn’t really thrown much in the last two weeks of the season. The last time I remember being in a close game was the day after we clinched [the division]. It was really tough to sit on the sideline and knowing I didn’t have a chance to get out there and watch us lose in the first round again. It was tougher to do that and knowing I couldn’t do anything to help.”

Detwiler understands what didn’t work well for him in 2014. He posted a 4.00 ERA and a 94 ERA+. His walk rate jumped up to 3.0 per nine innings, his highest mark since 2009. His 1.413 WHIP was highest among Nationals relievers. He went through stretches of strong pitching followed by ineffectiveness.

“I think the more I threw the better I did,” he said. “There were certain situations I was put in that I never really got used to. I got used to one role and then I got put in another one. It was kinda foreign to me. Learning what it felt like to be ready when you’re throwing out of the bullpen – I was loose but I didn’t really know – my mental approach was kinda thrown off. I have the stuff to get people out. I know that. It’s the mental approach and execution. And execution kinda fails when you don’t have the opportunity as much as you used to. There were times I’d be throwing and would just leave a pitch over the middle. Or I’d be ahead in the count and let the hitter back in by not getting the ball close or something like that.”

When the Nationals put Detwiler in the bullpen in spring training, Manager Matt Williams said the left-hander would be a hard-throwing weapon in relief. But Detwiler’s usage was sporadic, perhaps a byproduct of his performance, workload or lack of trust in him. Especially early in the season, Detwiler was rarely used in important situations, relegated to long-relieving or mop-up roles. And when Detwiler went several days to more than a week without pitching, the former starter said it affected his feel for the strike zone.

He tried doing what Craig Stammen did on occasion: throwing in the bullpen when the workload was light for a stretch. But that can be hard on the arm because relief work is so spur-of-the-moment that a pitcher could throw twice in a day. The adrenaline is also missing from a side session. Detwiler’s previous experience in the bullpen didn’t fully prepare him for 2014 because the circumstances were different.

“Before this year, I was always on a set schedule,” he said. “I wasn’t completely throwing out of the bullpen. … I was still on a starter’s schedule but throwing a lot less. That was a big change.”

Although Detwiler still believes he can start, his role in 2015 will be similar to last season, according to General Manager Mike Rizzo. At the GM Meetings in Phoenix earlier this month, Rizzo said he expects Detwiler to be a “rotation guy in case something happens.”

“If all five of our starters come back healthy and pitch throughout the season, I think he’ll be a valuable piece in the bullpen, kinda like he was last year,” he added.

Rizzo said Detwiler was still adapting to the bullpen last season. In the past, Detwiler has done well in the bullpen. “I think last year he showed flashes of being effective and inconsistencies at times, too,” Rizzo said. “I think he’ll be better equipped to pitch out of the bullpen if that’s his role with us next year.”

If is a key word. The deadline to tender contracts to arbitration-eligible players is Dec. 2. Asked if he would tender a contract to all of the Nationals’ arbitration-eligible players, Rizzo declined to answer.

But by evaluating the situation and comments, there are hints as to what could happen. If the Nationals trade a starter — perhaps Jordan Zimmermann or Doug Fister who each have one year left before free agency — Detwiler could be rotation insurance. (That would be a curious move given that the Nationals passed over Detwiler for the rotation in spring and during the season for fill-in starts.) If not, the Nationals could tender him a contract and bring him back in the same role as last year.

The situation with Detwiler, however, has perhaps reached a point where a clean break for both sides would be best. The Nationals had chances to move Detwiler in the past — other teams desperate for starting pitcher were interested — and didn’t. His value as a starter has taken a hit as he was moved into the bullpen and then left off the playoff roster, and he hasn’t started since 2013.

But the Nationals could still try to trade Detwiler. According to a person familiar with the situation, Detwiler’s camp has suggested to the Nationals that they pursue that avenue if possible. Detwiler is only 28, has a career 4.02 ERA as a starter, made perhaps the biggest start in Nationals’ playoff history (2012 NLDS Game 4) and could be a back-of-the-rotation starter for a major league team.

The Nationals could also non-tender Detwiler next week and save the $3.3 million he is projected to make in his final year of arbitration or use that money for another need. In the meantime, Detwiler would be a free agent and free to sign, perhaps as a starter, wherever he pleases.

Asked about his future role with the Nationals, Detwiler was blunt. He has been with the Nationals since they selected him in the first round of the 2007 draft. He has grown up alongside players in the system and made life-long friends. But he’s unsure what will happen.

“I don’t know,” he said about his future. “It’s kinda up in the air. They didn’t really tell me anything last year. … [I was asked by a reporter] ‘What do you think of the competition in the rotation?’ I was like, ‘What are you talking about?’ And at that point, it felt the same as in years past. They didn’t think I could get the job done and we’re going to move on and try to find some of our younger guys. At the beginning of the year, they took two of the younger guys instead of me because Doug [Fister] went down. That sucked. I don’t feel they have confidence so I don’t feel like I’m going to be in any significant role whatsoever.”