Jonny Gray believes Argentina have become one of the most dangerous sides in the world after sharpening their claws on their southern hemisphere rivals.

The Scotland lock has been impressed by the South Americans since they were admitted to the Rugby Championship back in 2014.

They have already recorded wins over both Australia and South Africa and this year had the All Blacks worried when they lead for half an hour in Hamilton before eventually succumbing to a late onslaught.

But Gray is concerned the Pumas could now pounce on his side when the Scots welcome Argentina to Murrayfield for Saturday's autumn Test clash.

He said: "Are they up there with the best sides in the world now? I'd say so.

"Argentina are a great team. They can attack from anywhere. Look at the players they have got - guys like Agustin Creevy, some of their backs and their huge wingers, so they have some dangerous strike runners.

"They are always keeping the ball alive so you can never switch off.

"When it comes to facing them up front, in the scrum and in the line-out it's going to be a huge challenge. Across the board we have to be switched on.

"You just have to look at some of their recent results in the Rugby Championship to realise they are a world-class side. They beat South Africa and then pushed New Zealand all the way.

"We have to be on it from minute one to the final whistle. We need to be clever, we can't be coughing up ball to them."

But while the Glasgow forward is preparing to face a side who have made significant strides forward in recent years, he believe he still has some way to go before he himself can claim to be among the world's top performers.

Gray has been tipped for a call-up to the British and Irish Lions squad set to tour New Zealand next summer.

His performance in Saturday's loss to Australia where he made all of his 24 tackles stick will have only improved his chances of making Warren Gatland's travel party.

But Gray is not putting too much emphasis on the statistics.

The 22-year-old said: "I don't look at numbers. As a defence we all work for each other. Whoever is there makes the tackle and whoever misses the tackle is there to help clean up.

"We play for each other, we play with a lot of heart, so it's a team effort, always.

"I'm just lucky I've got the coaches at Glasgow and Scotland who will sit down with me and show me where I can improve my game.

"It's really special getting to play for your country and to come up against some of the best second-rows in the world like we did at the weekend against Australia.

"It's a great opportunity to test yourself against these guys. I think I've got a lot to improve on and a long way to go before I'm at that level.

"But I'm lucky I've got players around me pushing me on. We're always pushing each other here."