Injured Yankees starter Phil Hughes had setback Monday in his rehabilitation from a "dead arm," cutting short a bullpen session after only about a dozen pitches.

Hughes went on the disabled list April 15 because of a significant drop in his velocity this season. The team was impressed with Hughes' progress and was planning to have him make a rehab start later this week, but he was not even able to complete an "inning" of 15 pitches.

"It's just the same as before," Hughes said. "It's like nothing's coming out ... just a lot of deadness, nothing really there after the first 10 (pitches) or so, so I'm just going to take a couple days, rest it and reevaluate it from there."

The right-hander saw team doctor Christopher Ahmad on Monday night and manager Joe Girardi said after the 2-0 loss to the White Sox that Hughes will have tests Tuesday.

"When you're not able to bounce back from your normal routine, that's a concern," Girardi said pregame. "When something like this happens, it is a concern."

The Yankees had high expectations for Hughes after he went 18-8 last year. But he was 0-1 with a 13.94 ERA after three starts and had trouble reaching 90 mph with his fastball. Hughes has acknowledged that throwing a career-high 176 1-3 innings last year could be affecting him.