The Orioles remained active in the trade market on Monday, making a deal just before the 4 p.m. deadline when they sent right-handed reliever Miguel Castro to the New York Mets for minor league left-hander Kevin Smith and a player to be named later or cash.

It was the Orioles’ third deal in two days. On Sunday, they traded starter Tommy Milone to the Braves and reliever Mychal Givens to the Rockies.

Castro, 25, who came to the Orioles in April 2017 from the Colorado Rockies for a player to be named later that turned out to be minor league right-hander Jon Keller, was 7-13 with a 4.06 ERA in four seasons with the Orioles.

Before Monday’s game, manager Brandon Hyde said that Castro hadn’t been used since Friday because he had sinus issues.

Castro was 1-0 with a 4.02 ERA and a save in 16 games with the Orioles this season.

Smith, 23, who was at the Mets’ alternate site in Brooklyn, was 8-7 with a 3.15 ERA in 23 games at High-A St. Lucie and Double-A Binghamton last season.

He was the 11^th-rated prospect, according to MLB Pipeline, and had 130 strikeouts in 117 innings in 2019.

When the Orioles play the Mets on Tuesday at Camden Yards, they’ll have to add a player to fill Castro’s roster spot.

There are 38 players on the 40-man roster and 58 in the 60-man player pool.