Scotland will have to find a way to let adopted Springbok Duhan Van Der Merwe gallop free against France if they are to avoid a repeat of their Tuscan trudge, according to Sam Johnson.

Gregor Townsend's team struggled to break free of a fired-up Italy on Saturday as they found themselves bogged down at the home of Serie A side Fiorentina.

The Dark Blues' scrum toiled as the football pitch at the Stadio Artemio cut up badly as the opposing packs got down to business, allowing the Azzurri to dominate the set-piece as well as the collisions during a sloppy first half.

Scotland's fitness levels eventually told as they came through to win their Autumn Nations Cup opener 28-17 with three tries after the break, with the performance of South Africa-born wing Van Der Merwe on just his third cap key to that turnaround.

The Edinburgh flyer is often accused of not doing enough to get himself in the action but he peeled off his wing brilliantly to score the first of four Scottish tries 24 minutes in and led the charge in the second half as Italy wilted.

And centre Johnson admits Scotland will need to work harder than they did at the weekend if they are to ensure they see more of Saturday's man of the match when Fabien Galthie's Les Bleus visit Murrayfield next Sunday.

Johnson – who missed last month's clashes with Wales and Georgia through injury – said: "That was my first time playing alongside Duhan. He's a great runner isn't he?

"He's a big, fast, physical man, so it'll be key for myself or anyone around him to just give him the ball and allow him to pin his ears back, which he did really well on Saturday.

"Why did we struggle during the first half? I think we just didn't grasp the size of the pitch. Being a football pitch it was a lot smaller pitch than we're used to, compared to say a Murrayfield.

"We didn't adjust our bearings quick enough, and Italy are a big, fast, physical team who got the better of us around the contact area. Set-piece was also a problem because we didn't get much good set-piece ball in that first half either. It was a credit to Italy really.

"But we rolled our sleeves up and adjusted well in the second half and I thought we played well and ended up on top.

"You've got to give Italy credit and respect. If any team in world rugby thinks they're going to rock up and win in Italy then they're in for a rude awakening.

"We knew they were going to be fast and physical, but that if we could stay in the fight and wear them down then our fitness was going to dictate who was the winner and that's how it turned out to be.

"What do we have to improve for France? It's around the contact area. If we can get speed of ball and outflank the defensive line then hopefully that opens up numbers out wide for guys like Duhan.

"So probably the biggest things are our contact area and the set-piece, because from a back's perspective it just felt like we weren't getting much first phase ball.

"I don't know why that was, but if we can fix it this week that'll be key for going up against a tough France team."

Johnson has only started two games for Glasgow this season on his return from a knee injury and his rustiness was evident as he threw a forward pass to Duncan Weir just after half-time, denying the stand-off a touchdown on his comeback run-out after four years in Finn Russell and Adam Hastings' shadows.

"I knew it was a forward pass when I threw it," admitted the Australian-born midfielder. "There was someone right behind me, but I think I probably had a bit more time than I realised.

"I was just trying to get it out of my hands to Duncan but I knew straight away that it was a forward pass.

"I didn't find the speed of the game too bad to begin with but I was beginning to search for my lung around the 60-minute mark.

"It was a completely different tempo and pace to club rugby. This is my third game back now so it's all about trying to get match fitness.

"We'll see what happens when I get back and see who Gregor picks for next week."