ARLINGTON -- When Danny Duffy took the mound in the seventh inning against the Rangers on Friday night at Globe Life Field, it was just his second relief appearance since the start of the 2017 season. He needed 15 pitches to get through the clean inning, with one strikeout and two soft groundouts.

It’s not going to be the last time the Royals use the veteran lefty in relief this year.

This is Duffy’s new role, at least for now. On Wednesday against the Yankees, he logged a two-inning start in his first outing back from a six-week injured list stint due to a left forearm flexor strain. Friday was his scheduled bullpen day. It gave the Royals an extra arm in an overworked bullpen that had a full bullpen game on deck for Saturday. Duffy is on track to start a game in Boston next week, but it’s going to be limited again.

And Duffy, who reached 10 years of service time on Saturday, is all for this hybrid role.

“I love the bullpen,” Duffy told MLB.com on Saturday. “I know my value to this team is starting, but if we could bring a little bit more to the table, talk about reciprocating with the bullpen guys down there who have had an intense workload, if we can give those guys a day off, that’s huge.

“I was really thankful [manager Mike Matheny] was able to give me that opportunity and willing to. Again, I know this isn’t some kind of audition for the 'pen. I know I’m a starter. But rather than wasting bullets, given the opportunity, I’d love to help out with it.”

To be clear, Duffy isn’t feeling pain from the flexor strain. His arm, he said, feels great. But he didn’t go on a rehab assignment when he was ready to return -- the Royals needed his arm at the big league level, and he wanted to be with them -- so he’s building innings on the job, with limited pitch counts during his starts and relief appearances in between.

“Building up during the season is difficult, especially when you don’t go on a rehab assignment,” Duffy said. “I think this is a good route to go. I like it. I welcome the challenge. If I could be of any kind of help, that’s what my job is. That’s what I’m going to do.

“With doing this essentially as my rehab assignment, I know that it’s going to be keeping the guys thin down there. And if we can go in between, instead of throwing on the side, being available out there, I’d love it. I was really fired up about the opportunity.”

It’s an unconventional route to go, and Matheny knows that. Duffy, Matheny, the team's medical staff and front office were all involved in the decision and believe it’s going to keep Duffy healthy and on the field. It also gives him an opportunity to try a new role while also keeping him in a starting role that he’s excelled in, especially this year.

Before he went on the injured list, Duffy was one of the best starters in the American League, posting a 1.94 ERA in seven starts (41 2/3 innings). With those innings, though, came soreness in his arm, which turned into enough discomfort that it warranted an IL stint.

This new plan might not be without its difficulties, as Duffy’s limited starts open the possibility of a depleted bullpen, which ranked sixth in the AL in innings pitched (287) entering Saturday. Matheny recognizes this, but he hopes the relievers who are stretched out -- Kris Bubic, Carlos Hernández and Ervin Santana, for example -- can help on those days.

“It depends on what your bullpen is consisted of,” Matheny said. “If it’s all one-inning guys, yes absolutely. If it’s comprised of some young players who have been stretched out or can be stretched out, then they could and should fill that void. I’m not going to sit here and convince any of you that it’s a flawless system. We’re trying to do something to keep a player healthy and trying to figure out what we can do differently than what has not worked in the past.

“It’s not going to go without its hiccups. I get it. I keep going back to, what’s the right thing here? Let’s be committed to doing the right thing. The right thing might not be conventional, but we believe there’s some science, other influences that make it the right move, and we’re going to give it a shot.”