09/26/2012 01:30 EDT | Updated 11/26/2012 05:12 EST

Locked out NFL officials could return soon: source

The battle between the NFL and its lockout officials could soon come to an end.

Sources on both sides have told ESPN’s Chris Mortensen enough progress was made during Tuesday night’s talks that the possibility of the regular officials working this week’s games had been discussed.

An agreement in principle is at hand, Mortensen reports.

According to league sources, the officials would need a week to get onto the field, but the National Football League's Referees Association said the 121 locked out referees are up to speed on the new rules put in place last season.

Officials have already passed or are ready to pass their physicals.

More to come