The use of personal electronic devices for work tasks—a central issue in past NFL disputes—has emerged as a point of contention in Minnesota Vikings defensive coordinator Brian Flores’ lawsuit against the NFL over alleged race-based employment discrimination.

Flores seeks evidence to further his claim that the league and several teams intentionally discriminated against him, and the coach has insisted his legal team gain access to personal devices of league and team employees for discovery purposes.

The NFL and teams involved in the lawsuit have pushed back. In a status report letter jointly filed by attorneys for Flores and for the NFL, Denver Broncos, New York Giants and Houston Texans in federal court on Monday, the league and teams expressed concern about Flores push for access to the devices.

The NFL sees personal devices as off-limits and Flores’ demand as unnecessary overreach. The league assigns electronic devices to employees to be used for work purposes, and teams ordinarily do the same with their employees.

The league argues that Flores wants access to employees’ personal devices “without any basis” and, allegedly, without establishing that current and former employees “use their personal devices for work-related purposes, or that their personal devices would contain any relevant discovery that is not duplicative of what is on a work-issued device.”