Walker (foot) will throw a light bullpen session Sunday, Alex Coffey of The Philadelphia Inquirer reports.

Walker (toe) is scheduled to do some throwing Monday, Corey Seidman of NBC Sports Philadelphia reports.

Walker was diagnosed with a left foot bruise after exiting Thursday's start, Matt Gelb of The Athletic reports.

Walker exited Thursday's start against the Mets after being struck in the left foot by a line drive, Matt Gelb of The Athletic reports.

Walker (3-0) earned the win Saturday against the Marlins, yielding just one run on eight hits and one walk over six frames. He struck out four.

Walker (2-0) earned the win over the Giants on Sunday, allowing three runs on five hits and a walk while striking out seven over 6.1 innings.

Walker (1-0) picked up the win over the Padres on Sunday, allowing six runs on eight hits and two walks while striking out four over 6.1 innings.

The Phillies reinstated Walker (shoulder) from the 15-day injured list ahead of his start against the Padres on Sunday.

Manager Rob Thomson said Walker (shoulder) will be activated from the 15-day injured list to start Sunday against the Padres, Alex Coffey of The Philadelphia Inquirer reports.

Walker (shoulder) struck out one and allowed four earned runs on seven hits and three walks over 6.1 innings in the third start of his rehab assignment Sunday with Triple-A Lehigh Valley.