Trinity had yet to win at the time Shaun Wane made his selection, but when he reviews the first half of yesterday’s 30-24 win over Salford Red Devils, the national coach may well be forced into a change of mind.
Johnstone’s head-to-head with Salford right-wing Ken Sio, who was Super League’s top try scorer last year, promised a fascinating individual battle and both finished the game with two tries, but the Trinity man was a clear winner.
He also provided the final pass for a try and was involved in another as Trinity opened a 24-4 half-time lead.
The 26-year-old’s brace took his tally of Super League tries to eight, the second of them being a world class effort.
Jacob Miller’s pass found him tight on the left flank and, with most of Salford’s defence massed in front of him, he cut infield, past a host of would-be tacklers, to score an almost impossible try on the final play of the first half.
That set had begun with Johnstone needing treatment on his back before being able to play the ball, after making a super airborne catch on his own line.
Injuries, including two knee reconstructions and a couple of concussions last season, have clouded Johnstone’s career and he did not come out for the second half.
With Trinity’s most potent threat no longer on the field, Salford staged an unlikely fightback, cutting the gap to just six points going into the final 10 minutes.
Wakefield’s fifth try, seven minutes from time, made the points safe, but Salford scored again on the final play.
Other than Johnstone’s brilliance, the crucial difference between the sides was Max Jowitt’s goal kicking.
In blustery conditions, he converted all of Wakefield’s tries, while Marc Sneyd managed only two successes for the visitors.
Johnstone looked dangerous from the start and provided the pass for Trinity’s opening try, after eight minutes.
A pass by Corey Hall, the young centre who has been a revelation since joining Trinity from Leeds Rhinos in pre-season, sent Johnstone into space and the winger unselfishly turned the ball inside to give Miller an easy stroll to the line.
Salford hit straight back through Rhyse Williams, from a Tim Lafai pass following a Wakefield error from the restart, but Johnstone increased Trinity’s advantage late in the first quarter, as Miller returned the favour from earlier.
The stand-off chipped a kick to the left flank and Johnstone leaped to grab the ball before a hesitant Sio, touching down one handed.
Jowitt was inches away from increasing the lead when he made a fine catch from another clever kick by Miller, but the full-back was grounded just short.
In the next set, Elijah Taylor split Wakefield’s defence, with Ryan Brierley in support, but lost possession. That was a huge let off for the home team and they made it count soon afterwards with a stunning counter-attack.
Johnstone fielded a kick behind his own line and went on a thrilling run, then - after he had been dragged down - managed to get the ball away to Wakefield’s other winger, Liam Kay.
He was also halted, but on the next play the ball was moved right and Reece Lyne skipped past Brierley to go over unopposed.
Three minutes before the break, Wakefield, in a display of confidence which might have come back to bite them in the second period, tapped a penalty in front of Salford’s posts and it almost paid off as Liam Hood went over from acting-half, but the touchdown was ruled out for a double-movement.
Even so, Wakefield would have been happy to turn around 14 points ahead. Instead, Johnstone’s wonderful second try sent Wakefield into half-time with a 24-4 lead.
Salford hit back with two tries in the third quarter.
Deon Cross went over after Ryan Lannon and Sam Luckley had both been held up across the hosts’ line; then - after a ball steal on Sitaleki behind the whitewash and desperate defence to prevent Chris Atkin touching down - Sio scored his ninth try of the league campaign.
With 14 minutes left, Wakefield attempted a short drop out, but Williams made the catch and raced straight over for Salford’s fourth try.
That cut Trinity’s lead to six points, but in the 72nd minute Mason Lino opted not to go for a one-pointer and instead kicked right to Kay whose offload sent Jay Pitts over to seal it.
With 28 seconds left, Wakefield’s Tinirau Arona was sin-binned for persistent infringements and Sio scored a consolation try for Salford from the penalty, Sneyd converting after the hooter.
Wakefield Trinity: Jowitt, Johnstone, Hall, Lyne, Kay Miller, Lino, Tanginoa, Hood, Arona, Ashurst, Pitts, Batchelor. Subs Battye, Whitbread, Crowther, Aydin.
Salford Red Devils: Brierley, Williams, Cross, Lafai, Sio, Croft, Sneyd, Vuniyayawa, Ackers, Gerrard, Taylor, Lannon, Ormondroyd. Subs Akauola, Burke, Atkin, Luckley.
Referee: Chris Kendall (Huddersfield).