The 24-year-old, who notched up 100 games for the senior club last ­campaign, makes the move to Queensland for work as a mining ­engineer this week.

Johnston has been a regular in the Blacks pack for several winters at either flanker of second-row, including a 2010 grand final appearance.

Johnston has represented Newcastle in successful NSW Country Championship carnivals and previously earned Cockatoos caps in the colts category.

This leaves new first grade coaches Mick Hickling and Ryan McCormack with a hole to fill before the opening round away against Southern Beaches on April 9.

Johnston departs along with skipper and last year’s No.8 Sean O’Connor, who will assist former first grade ­captain Luke Cunningham coach thirds.

However, Anderson Medal-­winning breakaway Nick Davidson returns and will be the mainstay of the Maitland forwards.

The Blacks first home match this year will be in the second round against Nelson Bay on April 16, according to a draft draw released by NHRU officials. 

A fixture against University at Marcellin Park on April 23 will be ­followed by a string of tough ­encounters with defending champions Hamilton (April 30 at Passmore Oval), grand finalists Wanderers (May 14 at Marcellin Park) and Merewether Carlton (May 21 at Townson Oval).

Singleton away (May 28), Lake Macquarie at home (June 4) and a visit to Waratah (June 18) rounds out the first half of the season. 

The Blacks have recently started pre-season training.

And this Saturday the club has entered sides in the Hamilton Hawks-run Michael “Whale” Currey Memorial Sevens being played at Charleston’s St John Oval.