The Philadelphia Phillies are getting closer to welcoming back their ace.

Right-hander Zack Wheeler is scheduled to make his first rehab appearance on March 23, marking a major step in his recovery from thoracic outlet surgery last September. Wheeler is expected to throw around 40 pitches as he begins building back toward game shape.

The 35-year-old hasn’t appeared in a game since August, but has steadily progressed through bullpen sessions and live batting practice without setbacks. Now, he’ll transition into game action.

Wheeler will miss Opening Day, but the current expectation has him trending toward a return sometime in April, assuming his rehab outings go smoothly.

For the Phillies, getting Wheeler back early in the season could be a massive boost to a rotation with World Series aspirations.