Finn Russell (left) and Adam Hastings have been selected as the main fly-halves, with Duncan Weir missing out

The depth of Scotland's Rugby World Cup training squad is "unmatched" by previous groups, says former national captain Rory Lawson.

Head coach Gregor Townsend named a group of 42 for the summer with two spots yet to be filled.

Second-row Richie Gray and fly-half Duncan Weir are two high-profile omissions.

"It's unmatched when you look at the quality of player and competition for places," Lawson said.

"When you consider the likes of Richie Gray, Duncan Weir and even a bolter like [uncapped Glasgow centre/wing] Kyle Steyn haven't been involved as yet it does show the depth that Gregor Townsend has."

Gray has only made one Test appearance in two years due to injury, but has returned to action for Toulouse who reached the semi-final of the Champions Cup and lead the French Top 14.

And Lawson, who represented Scotland at the 2007 and 2011 World Cups, would be "surprised" if Gray, capped 62 times, did not break into the squad.

"I would like to think if Toulouse continue to show the form they have, he would get that nudge as that extra position in the forwards because I think he brings a different skill set and a bundle of experience - something Scotland would benefit from," Lawson told BBC Scotland.

Weir, meanwhile, has rediscovered top form after leaving Edinburgh for Worcester last summer, having kicked 193 points- the second highest in the division- so far to help keep the English side in the Premiership.

However, Glasgow duo Adam Hastings and Pete Horne have been preferred initially as back-up to Finn Russell, with Horne also able to play at centre. And Lawson believes Townsend is looking for fly-halves who fit with the fast-paced style the national side play.

"I'm not sure he [Townsend] wants something different," Lawson said. "By having that similarity, you've got two players who play that way and you can build the performance of the side around.

"If you think back to my day and take Dan Parks versus Phil Godman as your fly-half battle - you've got two 10s who play a different way.

"It offers the team a different way of playing, but at the same time, you've got the other 14 players who would have to think differently depending who was at the helm. With Hastings and Russell, you get consistency."