The Orioles are perceived as controlling the market for late-inning relievers, because Zach Britton is drawing widespread interest across the industry. Based on volume, however, the Reds are the most influential bullpen seller of all.Sources say the Rockies, Red Sox, Braves and Phillies are among the teams that have checked

The Orioles are perceived as controlling the market for late-inning relievers, because Zach Britton is drawing widespread interest across the industry. Based on volume, however, the Reds are the most influential bullpen seller of all.

Sources say the Rockies, Red Sox, Braves and Phillies are among the teams that have checked with the Reds on a late-inning bullpen group that includes Raisel Iglesias , Amir Garrett , David Hernandez and Jared Hughes.

Among that group, one source said Cincinnati has no plans to move Garrett, but the other three are available.

The Reds have the luxury of maintaining high asking prices on their relievers, because each is under control beyond this year. Iglesias, Cincinnati's closer and most coveted reliever, can't become a free agent until after the 2021 season. Garrett, in his first season as a reliever, is under control for five seasons beyond the current one.

Meanwhile, the Reds wisely signed Hernandez and Hughes to two-year free-agent contracts last offseason. They have responded with ERAs below 2.00 this season: Hughes at 1.56; Hernandez at 1.75.

The Reds also could obtain a prospect for Matt Harvey, who has re-established his value since arriving in a trade with the Mets. As MLB.com's Mark Feinsand mentioned earlier Tuesday, the Brewers have checked in regarding Harvey.

Milwaukee does not appear to be engaged in active trade talks with Cincinnati about Harvey. Rather, the Brewers view Harvey as a fallback option if other rotation pursuits are unsuccessful.

Finally, one source said the Reds haven't made right-handed starter Luis Castillo available via trade. Castillo's value is down slightly from a sensational rookie season in 2017, and there's little urgency to trade him, anyway. Between Harvey and its relievers, Cincinnati will be busy enough over the next week.