Getty Images

A year after four NFL referees retired, two more will call it quits after lengthy careers officiating pro football games.

The league has announced that Pete Morelli and Walt Coleman will serve as co-referees for the Pro Bowl, adding that both will retire. Morelli has 22 years of service, and Coleman has 30.

Word of Coleman’s looming retirement previously had circulated. Morelli’s plans to retire weren’t already known.

The league will have to find a pair of new referees for 2019, at a minimum. Ed Hochuli, Terry McAulay, Jeff Triplette, and Gene Steratore retired after the 2017 season. That’s six new referees in two offseason, more than a third of the full staff of 17 referees.