Kevin Long is joining the Philadelphia Phillies as their hitting coach, according to a person with knowledge of the situation, taking the role he had with the Washington Nationals since 2018. At the end of the season, the Nationals offered Long a chance to remain with the organization. But he instead chose to reunite with outfielder Bryce Harper, Manager Joe Girardi and Phillies bench coach Rob Thomson.

Long, 54, was previously a hitting coach under Girardi with the New York Yankees. He and Thomson overlapped there, too, and Long was Harper’s coach for one season in Washington. Aside from being on the World Series-winning staff, Long has been a mentor for Juan Soto and helped keep the offense afloat in 2021. Despite finishing 65-97, Washington tied for the eighth-best on-base-plus-slugging percentage in MLB and ranked 16th in runs.

The departure marks another change for Manager Dave Martinez’s staff. Bobby Henley, his third base coach, and Randy Knorr, his first base coach, have already been moved to player development roles. That means at least three positions will have to be filled this winter. Aside from Long, Henley and Knorr, bench coach Tim Bogar, pitching coach Jim Hickey, bullpen coach Henry Blanco and assistant hitting coach Pat Roessler have been invited to return.

Of those four, Martinez announced that Hickey will be back in 2022; Bogar and Blanco also seem to be locks to stay with the team. Roessler, though, was hired at Long’s recommendation in December 2019. The pair had worked together with the New York Mets. As of Monday afternoon, a person with knowledge of the evolving staff was unsure of what Long’s exit would mean for Roessler. And while the terms of Long’s agreement with Philadelphia were not yet publicized, a person with knowledge of his plans said he was seeking a multiyear contract.

Last October, he briefly looked around for such a contract before signing back with Washington. He was open to returning again, according to multiple people familiar with the discussions, but ultimately landed with Girardi and the Phillies. In June, after MLB began its “sticky stuff” crackdown, cameras captured Long screaming at Girardi for asking for a check of Max Scherzer at Citizens Bank Park. It would seem that any lingering differences have been mended.

The Athletic first reported that Long was heading to Philadelphia. The Phillies had an opening after firing hitting coach Joe Dillon at the end of this season. Dillon, 46, was previously Long’s understudy in Washington and on the championship staff.

For the Nationals, losing Long could frustrate their best player. Long and Soto often stood side-by-side in the dugout, talking about hitting. Long helped Soto craft an extensive pregame routine in the batting cage. During the National League Championship Series in 2019, when Soto was in a mini slump, it was Long who stayed and drilled with Soto past midnight. Soto chose Long to throw to him in this summer’s Home Run Derby. And last week, the two of them were at Dodger Stadium to watch Scherzer and Trea Turner play in the NL wild-card game.

After Scherzer and Turner were traded at the deadline, Soto was frustrated about two friends — and two older brother figures — leaving the team. When asked whom he would lean on in their absence, he listed three people: first baseman Ryan Zimmerman, Blanco and Long. But with Long gone and Zimmerman contemplating retirement, the list is shrinking again.