PEORIA, Ariz. -- The Mariners made a second round of roster cuts on Friday, sending five players to Minor League camp, including right-hander Chase De Jong, the club's No. 22 prospect per MLB Pipeline.
Seattle optioned De Jong, who is on the 40-man roster, to Triple-A Tacoma.
The four other players -- right-handers Ryan Garton and Ljay Newsome, infielder Rey Navarro and catcher Joe DeCarlo -- were reassigned to Minor League camp as non-roster invitees.
De Jong, acquired from the Dodgers last spring, spent most of last season with Tacoma but did appear in seven games (four starts) with Seattle, posting a 6.35 ERA in 28 1/3 innings.
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Manager Scott Servais said the Mariners remain high on the 24-year-old, but they know he needs more development time.
"Some guys it comes very quickly, for others it's a step-by-step process," Servais said. "That's where Chase is. He's much more physical, you can tell just looking at him. He took his offseason very seriously. He's probably put on 15 good pounds. Stuff-wise, he continues to get better, and he's added some things in his delivery to kind of disrupt the timing a little."
Neither Garton or Navarro had played this spring. Navarro injured his right hamstring early in camp, while Garton is still recovering from offseason hip surgery.
Newsome earned an invitation to camp after winning a competition last year among all Mariners Minor League pitchers based on throwing strikes early in counts, while DeCarlo is a 24-year-old who converted to catcher last year and was one of six backstops in camp.
With the moves, the Mariners now have 56 players in Major League camp. Minor League camp opens Monday, with games set to begin Friday.