Walker (undisclosed) was reinstated from Triple-A Syracuse's 60-day injured list last Tuesday and has struck out seven while giving up one earned run on three hits and one walk across 4.1 innings in two appearances since being activated.
Walker had been on the shelf all season with an unspecified injury that he apparently picked up in spring training. He was finally cleared to rejoin the Triple-A club last week after he turned in a 1.17 ERA, 0.91 WHIP and 15:4 K:BB across 7.2 innings over a four-appearance rehab assignment in the lower levels of the minors.