Richard Cockerill’s side were drawn against the French heavyweights in the last 16 of the Heineken Champions Cup in what should be a fantastic match.
Racing reached the final last year and are arguably the most exciting club side in European rugby at the moment, boasting a backline that includes Finn Russell, Virimi Vakatawa, Simon Zebo and Juan Imhoff.
For Johnstone, a Scotland sevens international, it’s a chance to lock horns again with Vakatawa, Racing’s outstanding Fijian-born French international.
“I’m pretty excited, to be honest. It’s a great draw,” said the Edinburgh man. “They’ve got some great quality players but we’ve shown in the past when we’ve got it right what we’re capable of. But you need to be at your best to beat these sort of teams. We know we can compete with them and it will be a great challenge.
“You just want to test yourselves against the best in the game. You play rugby to be involved in the big games against the big teams.
“We obviously know Finn pretty well. He’s a fantastic player so it would be great to come up against him. I played against a few others at sevens back in my time like Vakatawa at No 13 so it would be great to play against him if I were selected. He’s a great player.
“How do you stop him? Good question! He’s a pretty good all-rounded player. It’s just about taking away time and space from these guys. You don’t want to allow them huge run-ups as they’re very good at manipulating defences. It’s just about getting stuck in to be honest. That’s how we approached it before. You can’t hesitate against these sorts of guys or they’ll cut you to ribbons.”
Before Paris, Edinburgh must resume the quest for Pro14 points and this weekend’s match takes them to Galway where they will face Connacht on Saturday night.
“It’s always a tough place to go,” said Johnstone. “Connacht have been playing some good rugby this year. We need to be on it on Saturday.”