The Miami Marlins have bolstered their  already strong bullpen even more with the addition of reliever Aaron Crow, acquired in a trade with the American League Champion Kansas City Royals on Friday. The Marlins sent pitching prospects Brian Flynn and Reid Redman back to Kansas City in return. MLB.com's Joe Frisaro announced the trade early Friday afternoon.

#Marlins acquire RH reliever Aaron Crow from Royals in exchange for LHP Brian Flynn and RHP

— Joe Frisaro (@JoeFrisaro) November 28, 2014

Crow, age 29, had a terrific record out of the Royals' bullpen, going 6-1 with three saves, but he did have a relatively high ERA of 4.12 in 67 appearances. Allowing 24 walks and 10 home runs in 59 innings did not help as it led to a WHIP of 1.29. 

Frisaro reminds us that Crow has lost more than two miles per hour off his fastball from his All-Star rookie season of 2011 to this year; his average speed dropped from 94.5 mph then to 92 mph this year. His strikeouts per nine innings have also dropped each season from 9.4 to 5.2. Still, he has had a very solid career record of 20-11 with a 3.43 ERA and 1.32 WHIP in his four seasons with the Royals, and he has started to mix in his slider more to keep hitters off balance. This track record demonstrates that power alone does not get Major League hitters out.

Crow is under team control for two more years, and he is eligible for salary arbitration later this offseason. He made $1.475 million in 2014.

The Marlins' bullpen finished seventh in the National League in ERA in 2014, posting at 3.33. Their top seven relievers in terms of appearances all had ERA's of 3.38 or below. Adding Crow, a lesser-known but proven reliever, will give the Marlins more flexibility out of the bullpen -- as well as stability. Crow has no injury history while in the Major Leagues, and he has made between 57 and 73 appearances each year since 2011. His 67 appearances in 2014 would rank him tied for third on the Marlins' staff with closer Steve Ceshek. The Marlins expect to Crow to set up Ceshek, who saved 39 games in 43 chances this past season.