Walker will start at first base and will bat eighth Wednesday against the Nationals, Scott Lauber of The Philadelphia Inquirer reports.

EDGE Analysis

He'll step in as a replacement for Rhys Hoskins, who is presumably getting a maintenance day after starting in every game for the Phillies since Aug. 13. Walker also filled in for Hoskins that day, but in between, he made only one other start for Philadelphia (on Aug. 20). The veteran infielder is hitting .192 over 28 plate appearances this season, and he may have find himself on the chopping block when Scott Kingery (back) eventually returns from the 10-day injured list.