Salas has been working out at the team's academy in the Dominican Republic since Spring Training began, as he was unable to report to camp due to visa problems.
The right-hander reported to the team's Spring Training facility on Thursday.
"It's good to have him out of the homeland and back in the United States," Rays manager Joe Maddon said.
Salas was placed on the 30-day restricted list on Thursday. General manager Andrew Friedman said the restricted list would in a sense be utilized as Salas' Spring Training, and Salas could come off the list early. He threw a short bullpen session at the club's Naimoli Complex on Thursday, but it is still unclear what kind of shape he is in.
Friedman said the club would monitor Salas' progress over the next week and put a more exact game plan together about his future.
"We are relieved this process is over and we are excited to get Juan to the States and get him back pitching," Friedman said. "Physically, he looks great. Now it's just a case of building up his arm strength and getting him in a position to go compete against hitters. We'll have a better feel for when he'll be ready to do that in seven to 10 days."
The 6-foot-2, 230-pound right-hander pitched in 34 games in 2007, compiling a 3.72 ERA out of the bullpen in more than 36 innings of work.
Joe Kieser is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.