"But his spell meant we could rest some of the first team players longer they ended up playing for about 20 minutes each in the reserve's game," he said.
Hall's sacrifice didn't help the first team though - they went down 2-0 to remain winless in the competition, conceding two first half goals.
Johnston said it was a forgettable, disjointed team performance in the first spell.
"We played much better in the second half we relaxed on the ball a bit more and played well but still couldn't break through and score."
It's a familiar story for the understrength team. Johnston said the squad could do with a few more players to help it get through their current dilemma.
"When we get back Steve Schimmel from suspension and a few other players who've been injured or have been away, we'll be okay, but for now we're really light on numbers, any injuries or suspensions and we're struggling," he said.
Anyone keen on playing should contact Graham Hall - chances are he'll be extremely happy to hear from you.