The Philadelphia 76ers closed out the Washington Wizards on Wednesday night in Game 5, advancing to the Eastern Conference semifinals. The top-seeded Sixers are set to play the fifth-seeded Atlanta Hawks, who dispatched the New York Knicks in five games in round one.

Philadelphia has not reached the Conference Finals since 2001. Atlanta’s last appearance in the East Finals came back in 2015.

The biggest storyline surrounding this series will be Joel Embiid’s health. The Sixers’ superstar center missed the Game 5 victory with a small lateral meniscus tear in his right knee. Embiid is considered day-to-day, but there’s a real chance he is sidelined for the whole series.

With Embiid’s status in limbo, let’s look at the 76ers’ x-factor for this series against the Hawks.

Why Dwight Howard is the X-factor for Sixers

If Joel Embiid is unable to suit up for part (or all) of the East semifinals, Sixers backup center Dwight Howard will be thrust into heavy playing time. Howard did not receive the start in Game 5 versus the Wizards, but that will almost certainly change in a matchup against the Hawks, who roster Clint Capela. A 6-foot-10, 240-pounder center, Capela led the NBA in rebounding this season, producing 14.3 boards per contest.

Capela’s biggest impact may be on the defensive end, however. In the team’s first-round series against the Knicks, the Hawks allowed 11.9 fewer points per 100 possessions with Capela on the floor than they did with him on the bench.

A dominant presence on the glass and an elite rim protector, Capela will see all the minutes he can handle against the 76ers—which means that Howard should play a major role next round. The 35-year-old Howard, who in his heyday was the best center in basketball, has settled into a backup role nicely with the 76ers. He will in all likelihood join the starting five and could see minutes in the high 20’s or low 30’s. That would represent a big uptick in playing time for Howard, who averaged 17.3 minutes per contest in the regular season.

While the 76ers are not expecting the All-NBA and Defensive Player of the Year version of Howard, they can rely on him to do what he has done well all year: rebounding on both ends of the court, shot blocking and setting screens. Howard has done a commendable job filling in for Embiid when the latter was sidelined this season. Howard registered per-game marks of 9.4 points, 10.6 rebounds and 1.1 blocks in 21 games without Embiid this season.

The 76ers finished first in the Eastern Conference on the strength of their defense. Embiid played a major role in forming one of the premier defenses in the NBA.  However, point guard Ben Simmons had as much, if not more, of an impact defensively. The 76ers will count on Simmons to slow down Hawks superstar Trae Young, who dominated the Knicks in the opening round.

Young is a sensational offensive player, so he will make his presence felt offensively. But he probably won’t score and distribute with as much ease going up against Simmons. With Young in a difficult 1-on-1 matchup, the Hawks will need more sources of offense. Capela might be called on to post up more. If Capela is indeed being fed the ball in the paint, Howard is the Sixers’ best bet to slow him down.

The Sixers signed Howard in the offseason for a reason. They knew Embiid’s lengthy injury history and were aware they might have to call on a backup to fulfill the center duties. In order to combat Capela down low, the 76ers need Howard’s big frame. Howard was brought to Philadelphia for this exact moment and his play could dictate if the Sixers cruise to the East Finals, or if the Hawks make this a lengthy, back-and-forth series.