OAKLAND -- The sight of infielders Hiro Nakajima and Adam Rosales doing work on the field Tuesday signaled progress in their respective rehabs.
Nakajima, though, lasted not much more than 10 minutes before returning to the clubhouse, while Rosales got some light throwing and running in, which would seem to indicate that his strained intercostal muscle might not keep him out much longer than his 15-day disabled list stint requires.
"I don't know yet," Melvin said. "Those injuries are really tough to predict until [Rosales] really starts swinging."
Rosales is eligible to return as soon as April 10. Nakajima can be reinstated the next day, though the A's likely won't rush his return as long as shortstop Jed Lowrie remains healthy.
"The first step is to get him on the field and get him moving around," Melvin said, "and then we'll have a better indication of how he's feeling."
The A's leave Oakland on Thursday evening for a six-game road swing through Houston and Anaheim, and it's unclear whether Nakajima will join them on the trip. There's a good chance he remains in the Bay Area to continue his rehab and prepare for a stint with one of the A's nearby Minor League affiliates.
"It depends on how close we think he is," Melvin said. "If we feel like he's close enough to where we want to watch him doing game activities, then we'll take him on the road."
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.