MIAMI -- When Derek Dietrich cleared waivers and opted for free agency on Monday, it not only marked the end of the longest tenure of any player on the Marlins' roster, it also created an opening in left field.
Dietrich broke in with Miami in 2013, and he was the starter in left on Opening Day in '18. In all, he played 97 games at the position, with 84 starts.
But with the Marlins ready to move in another direction, Dietrich's playing time in the outfield diminished in the final two months. He had a solid season at the plate, batting .265/.330/.421 with 16 home runs and 45 RBIs. In the outfield, though, he had his troubles. According to FanGraphs, he was minus-15 in defensive runs saved in left field.
As the Marlins get ready for the Winter Meetings on Dec. 10-13 in Las Vegas, the organization has prioritized finding experienced corner outfielders.
Internally, Miami has five players on the 40-man roster who could wind up in left field at some point in 2019.
1. Austin Dean 
The 25-year-old enjoyed a breakout season in the Minor Leagues, combining to hit .345/.410/.511 with 12 home runs and 68 RBIs at Double-A Jacksonville and Triple-A New Orleans. Dean's strong season earned him the Marlins' Minor League position player of the year honors.
Dean was called up in August and given a chance in left field down the stretch. In 34 games, he hit .221/.279/.363 with four home runs and 14 RBIs. Dean will get a chance to make the Opening Day roster in Spring Training, either as a starter or the fourth outfielder.
2. Isaac Galloway 
Galloway is a testament to perseverance and patience. The 29-year-old spent parts of 11 seasons in the Minor Leagues before getting his first big league opportunity in August.
Galloway appeared in 43 games with Miami, but he mostly came off the bench in the late innings. In just 64 at-bats, he hit .203/.301/.391 with three home runs and seven RBIs. At Triple-A, Galloway batted .262/.315/.429 with nine home runs and 30 RBIs.
Galloway's skill set is similar to former Marlins outfielder Cameron Maybin.

3. Garrett Cooper 
Not many may recall, but Cooper was the Marlins' starter in right field on Opening Day. But his tenure there didn't last long, because in the second game of the season, he was struck on the left wrist by a pitch and missed almost the entire season. Cooper appeared in just 14 games and had 33 at-bats (.212 batting average) in his first season with Miami. He underwent wrist surgery in September, and the hope is he will be ready for Spring Training. Still, missing so much time, coupled with coming back from major surgery, the Marlins will be careful with Cooper's recovery. But if he isn't ready for Opening Day, Cooper certainly should be good to go in the regular season. Even if he spends some time at Triple-A to get his timing back, Cooper could eventually be an option in left.

4. Magneuris Sierra 
For the most part, the Marlins did a nice job of not rushing rookies to the big leagues. Perhaps the one player who could have used more time at Triple-A was Sierra. The 22-year-old played 54 games for Miami and hit .190/.222/.211 in limited action. Because of injuries, Sierra was promoted from New Orleans, where he hit .260/.287/.341 in 86 games. His progression was hindered from the outset, when he suffered a left hamstring strain in Spring Training. In the offseason, the Marlins have asked the speedster to work on his bunting to make that more part of his overall game.

5. Monte Harrison 
Miami's No. 2 prospect, according to MLB Pipeline, Harrison recently was added to the 40-man roster. The 23-year-old slugger will be one of the most watched players in Spring Training, because he is getting closer to being big league ready. Harrison spent the entire season at Double-A Jacksonville, and despite belting 19 home runs and driving in 48 runs, he paced all of Minor League ball with 215 strikeouts. At Jacksonville, he had a .240/.316/.399 slash line. Harrison made an adjustment in the Arizona Fall League, reducing what was a higher front leg kick, and his timing improved. He hit .290/.383/.348 in the 19 Fall League games. When Harrison shows he can make consistent contact, he projects to secure a corner-outfield spot with the Marlins.