MINNEAPOLIS — After more than a month off, the NFL and its locked-out players have starting talking again about how to resolve their differences and ensure there is pro football played this fall.

The only sign of progress or productivity, though, was the nine hours or so both sides spent in the federal courthouse on Thursday.

Sworn to secrecy about specifics of the court-ordered mediation, neither the league nor the players provided much insight about where they’re at in their dispute over the division of this $9 billion business. They were set to meet again Friday.

Commissioner Roger Goodell, Carolina Panthers owner Jerry Richardson, Kansas City Chiefs owner Clark Hunt, Pittsburgh Steelers owner Art Rooney and New England Patriots owner Robert Kraft were among those on hand for the closed-door session Thursday.

NFLPA executive director DeMaurice Smith was joined by attorneys, linebackers Ben Leber and Mike Vrabel, as well as Hall of Fame defensive end Carl Eller.

“We had a full day. It was constructive to get together,” said Jeff Pash, the NFL’s lead negotiator. “The chief magistrate judge is working very hard, and I give him a lot of credit for really trying to move the parties toward a solution.”