Yankees top prospect Manny Banuelos was placed on the seven-day disabled list Friday after experiencing back pain during his second start a day earlier.

Banuelos, ranked by MLB.com as the No. 13 prospect in baseball entering 2012, will miss at least a week, although the team said there is no timetable on his return.

Banuelos, 21, has endured a rough start to the season with Triple-A Scranton/Wilkes-Barre, allowing 21 baserunners in 5 1/3 innings over two starts. He's 0-1 with a 10.13 ERA and has walked seven batters.

On Thursday, the Mexican southpaw issued six walks, allowing two runs on three hits over two frames at Buffalo. He was charged with four runs on 11 hits and a walk in his 2012 debut in Syracuse on April 7.

Banuelos was a MiLB.com Yankees Organization All-Star last year after going 6-7 with a 3.75 ERA in 27 starts between Trenton and Scranton/Wilkes-Barre. He competed for a spot on New York's Opening Day roster this spring but was assigned to Triple-A as expected.

Banuelos and Scranton/Wilkes-Barre are spending the entire season on the road as their ballpark, PNC Field in Moosic, Pa., undergoes renovations.

The Yankees promoted right-hander Chase Whitley from Double-A Trenton to replace Banuelos, and he ended up picking up the win in the Yankees' 7-5 victory in Buffalo on Friday, allowing one hit over four innings of relief. Whitley was a 15th rounder from 2010 out of Troy (Ala.) University who had struck out seven over four scoreless innings of relief in two appearances at Trenton.