De Leon noted the back problem was nothing more than a little tightness and nothing to be concerned about.
"And they were preventing, being cautious, and so they decided to skip a bullpen," De Leon said. "I'm ready to go. I'm feeling great.
"Everything is perfect. I threw my first live BP on Thursday and felt pretty good. So, I'm excited. I want to be in games."
When will Rays fans first get to see the 24-year-old right-hander this spring?
"I'm throwing live BP tomorrow, then I'll be ready to go in games," De Leon said. "Probably Wednesday or Thursday."
Last year, De Leon was rated as the Dodgers' No. 2 prospect, per MLBPipeline.com. He broke into the Major Leagues in 2016, going 2-0 with a 6.35 ERA over four starts in September.
A Puerto Rico native, De Leon was selected by the Dodgers out of Southern University in the 24th round in the 2013 Draft. He owns a 3.35 ERA with 446 strikeouts through four seasons (67 games, 64 starts) in the Minors.
Bill Chastain has covered the Rays for MLB.com since 2005.