LAKELAND, Fla. -- Aaron Judge is clocking overtime in the trainers’ room as the Yankees attempt to prepare the slugger for his first Grapefruit League at-bats of the spring, and manager Aaron Boone has been encouraged by the progress of that exercise.

“I would say I feel a little more optimistic today of where we're at,” Boone said prior to the Yankees’ contest against the Tigers at Publix Field. “It’s just how I’m feeling.”

Judge had an MRI performed on Friday in hopes of determining the cause of his right shoulder soreness, which Boone said reappeared after Judge took swings in an indoor batting cage this week. Boone has described the discomfort as being close to Judge’s right pectoral muscle.

The MRI and other tests were negative and Judge is scheduled to undergo more testing during Monday’s off-day.

One of the Yankees’ earliest-arriving players, Judge was performing hitting and throwing drills at the club’s Minor League complex in late January, but he shut down those activities prior to the Feb. 17 report date for Bombers' position players and has not hit on the field since. Judge recently threw at distances up to 120 feet.

“It’s a similar feeling he had when he was down here a couple weeks early, working and going through everything,” Boone said. “He was getting that discomfort, and it returned when he really started ramping up the last few days.”

Despite the stalled return to the batter's box for Judge, Boone said that he continues to believe the slugger could be ready for the March 26 season opener against the Orioles in Baltimore. The Yankees have also not ruled out an Opening Day start for Giancarlo Stanton, whose Grade 1 right calf strain is said to be improving.

Otherwise, Boone listed Miguel Andújar, Clint Frazier, Rosell Herrera and Mike Tauchman among the candidates to flank Brett Gardner in the outfield.

“I'm very optimistic on both Aaron and Giancarlo not being long-term things,” Boone said. “I feel good about the prognosis of things, even though in the immediate [picture] -- because of what has happened and what went on last year -- the flames get a little fanned.”