A day after Britney Spears checked out of rehab after a one-day stay, her estranged husband, Kevin Federline, will be in court amid a custody dispute over their two sons, the Associated Press reports.

Federline, 28, and his attorney, Mark Vincent Kaplan, are scheduled to appear at a downtown Los Angeles courthouse Thursday for an emergency hearing in family law court, Superior Court spokesman Allan Parachini told the AP.

It was not known what issue Federline plans to raise, but Spears, 25, is not expected to appear. “Our best information is he will be here; she won’t,” Parachini said. “But anything is possible.”

Kaplan will try to convince the court that whatever he is concerned about is so urgent that it needs to be fast-tracked, Parachini said.

Federline filed a claim seeking sole custody of his and Spears’s sons Sean Preston, 17 months, and Jayden James, 5 months, after Spears filed for divorce in November.

In early January the exes agreed upon a temporary arrangement granting Spears primary custody of the boys, with visitation rights for Federline. On Feb. 1 that arrangement was extended through the end of this month.

Because Spears can designate somebody to look after the children in her absence, the arrangement will remain “status quo” even if she is in rehab, Manhattan divorce attorney Nancy Chemtob says.

Federline’s lawyer did not return a call by the AP seeking comment.