PHOENIX -- The D-backs added another piece to the bullpen Thursday, signing right-hander Scott McGough to a two-year deal with a mutual option for 2025.

Improving the bullpen was priority No. 1 for Arizona general manager Mike Hazen; so far the team has Carlos Vargas, Cole Sulser and Miguel Castro, and now McGough.

McGough, 33, pitched in relief in Japan for the Yakult Swallows over the past four seasons, appearing in 236 games and going 15-8 with 80 saves and a 2.94 ERA. He struck out 251 over 232 2/3 innings.

"We’re happy we got this done," Hazen said. "I think we added another guy that’s going to pitch in the back end of our bullpen. He’s closed a number of games in Japan the last couple of years, so he has that experience, and we feel like that, with a combination of stuff -- the development of his split over there -- were probably the biggest selling points for us trying to go after him."

Not just adding arms, but adding power arms to the bullpen was a chief goal for the D-backs. McGough has a fastball that sits in the mid-90s, and he's shown an ability to throw it for strikes.

This is not the first time the D-backs have dipped into the overseas market.

In 2018, they signed right-handed reliever Yoshihisa Hirano from Japan and he posted good numbers for them that year before struggling a bit the following season.

Then in 2019, the D-backs inked right-handed starter Merrill Kelly from Korea. He has proven to be a big part of their rotation over the past four seasons. Kelly signed a contract extension with the D-backs in the spring and will pitch for Team USA in the World Baseball Classic next spring.

Seeing the success that a pitcher like Kelly had after spending four years in Korea -- as well as other players like Miles Mikolas, who pitched in Japan before signing with the Cardinals -- made the D-backs more confident that players can really benefit from their time spent overseas.

McGough's sole big league experience came in 2015 when he appeared in six games with the Marlins and had a 9.45 ERA.

"I think there’s probably been more comfort over the years with understanding that these transitions aren’t coincidental," Hazen said. "Guys go over there and do get better, maybe, again, just through pure opportunity. In this case, we felt like he developed [a splitter] and that was interesting for us."

McGough pitched for Team USA at the 2020 Olympic Games and led the staff with five appearances.

The D-backs are not done looking to add more relievers, but as it stands right now, Hazen can envision an open competition for the closer's role in Spring Training.

"We’re trying to acquire guys that are going to be in competition and have an opportunity to close," Hazen said. "[D-backs manager] Torey [Lovullo] likes to have a closer, so we’re not opposed to doing that if we find the right guy. I think [the front office is] a little more flexible as to having multiple closers. I’m guessing we would go into Spring Training and look to solidify a closer. But that’s more of a Torey question once we get to Spring Training."