Walker will serve as the Giants' opener for Wednesday's game against the Rays, Susan Slusser of the San Francisco Chronicle reports.

EDGE Analysis

Walker turned in a good performance during his last time out as San Francisco's opener Monday, throwing two scoreless innings and striking out four batters. The 27-year-old righty has been extremely effective with a 2.28 ERA through 43.1 innings this season, but he'll likely only remain in the game for the first two or three frames.