A Seattle Mariners trade is in place with the Miami Marlins that will send four prospects to the National League for pitcher David Phelps. Mariners general manager Jerry Dipoto is trying to add depth to the pitching staff and saw Phelps as a weapon that the team could use down the stretch. Having to give up four prospects to acquire him might seem very expensive to Mariners fans though.

David Phelps is a 30-year-old pitcher who has been having a good season for the Miami Marlins. He has appeared in 44 games for the team, posting a 3.45 ERA and 1.34 WHIP.

Phelps strikes out hitters at a rate of 9.8 per nine innings and has an impressive ERA+ of 119. Last season, he posted a 2.28 ERA and 1.142 WHIP over 86 2/3 innings of work for the Marlins.

Who did the Mariners trade to the Marlins for David Phelps?

In exchange for David Phelps, the Seattle Mariners had to give up outfielder Brayan Hernandez and pitchers Brandon Miller, Pablo Lopez, and Lucas Schiraldi. Hernandez was considered the sixth ranked prospect in the Mariners’ organization, while Miller was No. 16 and Lopez was No. 22. On paper, it may seem like a very expensive price to pay for a pitcher many Mariners fans aren’t familiar with.

Brayan Hernandez is with the Everett Aqua Sox and has posted a .259 batting average with two home runs and 15 RBIs through 31 games and 108 at-bats this year.

He was an international free agent and is still just 19. Brandon Miller has been playing for the Clinton Lumber Kings, where he has a 9-4 record, a 3.65 ERA, and a 1.18 WHIP over 18 starts and 101 innings pitched this season. He has a really good slider that projects him to make the Miami Marlins at some point in the future.

What are the Mariners doing with this trade?

On the surface, this may seem like an expensive package for the Seattle Mariners to give up, especially because some of the players look to have a really nice upside. The Mariners are clearly putting together a roster to compete this season and next year, though, so Jerry Dipoto has to deal some of the younger assets to achieve the goal of the postseason.

There are additional Seattle Mariners trade rumors, as the team has been speaking with the San Francisco Giants about acquiring more pitching. Names like Johnny Cueto and Jeff Samardzija have been mentioned, but they could be very expensive. After sweeping the Chicago White Sox over the weekend, the team is making a run up the Wild Card standings, suggesting this deal with the Marlins could be one of several that takes place involving the Seattle Mariners before the MLB trade deadline.