Dr. James Andrews performed Upton's surgery on Nov. 11 in Birmingham, Ala., repairing the labrum in his non-throwing shoulder.
On Wednesday morning, Upton worked out at Tropicana Field with a large contingent of Rays players while his dog, a Rhodesian Ridgeback named Deuce, patrolled the outfield with the gusto of his master.
When asked to render his gut feeling on whether he would be ready for Opening Day, Upton said he hoped he would, before adding a touch of caution.
"If not, hopefully [I'll be ready] when they get back off the road from playing [at Boston and Baltimore]," Upton said. "They said cold weather's probably going to be an issue with it. It's probably going to make it ache a little bit. I'm going to be careful with it, so hopefully when they get back off the road, I can start up."
Predictions aside, Upton said his shoulder is progressing nicely.
"[It's] coming along a lot faster than we thought it would," Upton said. "But at the same time, we can't rush it. Every time I come in, it feels better and better. So as long as we can keep doing what we're doing right now, it should be good."
Upton, 24, hit .273 with nine home runs, 67 RBIs and a career-high 44 stolen bases in 2008. However, he dealt with unspecified left shoulder damage, which was a big reason why his home run total dropped by 15 from '07.
"I knew there was something wrong the whole time, but I chose to stay on the field and play," Upton said. "That was my decision and I had to deal with what came with it. And luckily we still had a good year."
Upton said the club's offseason acquisitions of outfielders Matt Joyce and Gabe Kapler, along with designated hitter Pat Burrell, helps his outlook while recovering.
"We've got some guys out there who can hold it down, obviously, while I'm gone," Upton said. "We've got guys who can fill in the spots."
Upton said he "won't be swinging much" during Spring Training, but he will be in the field "running down fly balls."
"I should be able to do all of that," Upton said. "[I] just have to limit my swinging."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.