HE knew James Forrest was on a fast-track to the top way back in their Scotland U19 days.

But now Callum Booth is determined to derail his pal’s latest Treble bid and pile on the misery for Celtic after their shock Europa League loss to Copenhagen.

The St Johnstone defender knows it’s easier said than done. But he reckons Tommy Wright’s men will take confidence from last week’s 2-2 draw with Rangers, which edged Celtic a step closer to a ninth successive Premiership flag.

Winger Forrest has been a persistent thorn in Tommy Wright’s side, bagging four in a 6-0 McDiarmid rout last season and another in Celtic’s 3-0 January stroll.

“He is difficult to stop,” admitted Booth, who has steadied the Perth backline since recovering from an ill-fated summer switch from Dundee United to cash-crippled Bury.

“I have known James for a number of years and played with him for Scotland Under-19s all the way through to the 21s.

“He is quite quiet off the pitch and a really nice guy.

“We were in various squads together, going here, there and everywhere.

“You could tell he was a player even back then.

“We did have good sides with a lot of talented guys but James always had such great talent and pace over the first five yards.

“We have stayed in touch. It is a tough task to play against him but I have done it a few times over the years now. Obviously, he is a top, top player.”

Forrest has notched 16 goals already this term but left-back Booth knows Celtic carry goal threats all over the field.

They have won seven on the spin at McDiarmid, clocking-up 25 goals along the way.

“I think James scored a hat-trick when I played against him for Partick Thistle but we won’t mention that!,” he said.

“To be honest, he makes himself a striker sometimes so maybe we weren’t in direct opposition. He also had a spell playing on the left for a while…

“Seriously, I have had a few good battles with James over the years.

“He is a very dangerous player. He is also a quality player and I do hope I come up against him on Sunday.”