Castillo was one of several pitchers to complete a long-toss session at Tropicana Field on Monday, Marc Topkin of the Tampa Bay Times reports.

EDGE Analysis

The 26-year-old was joined by bullpen mates Jose Alvarado and Nick Anderson in getting work in Monday, and the group could be throwing live batting practice to teammates by Wednesday, as per Topkin. Castillo is still expected to have an important eighth-inning role in 2020 ahead of the likely closer duo of Anderson and Alvarado, but with a 60-game regular season now on the horizon, it's possible manager Kevin Cash also uses the trio (including Castillo) more liberally in the late innings than he would have in a more conventional campaign.