English-born centre Rory Hutchinson earns a first call-up by coach Gregor Townsend after an impressive season with Northampton Saints.

Glasgow Warriors hooker Grant Stewart and Scarlets forward Blade Thomson, both also uncapped, are recalled.

Edinburgh back-row John Barclay is included as he eyes a third finals.

A forward and back will be added as Townsend gives players the chance to "play their way into the group", which will eventually be cut to a 31-man group heading to the finals in Japan.

Townsend said: "We made a conscious decision to keep squad numbers low, which enables us to do more work with those most likely to be on the plane to Japan.

"There are of course a number of very good players who have missed out - players who have been unlucky with injuries this year or haven't hit form at the right time - while others are unlucky to lose out on some very close decisions."

Pro14 title-chasing Glasgow contribute 17 players to the squad, while Edinburgh have 13.

Just under half - 14 - of those named featured in the 31-man squad that reached the quarter-final of the 2015 tournament in England.

Townsend will initially work in smaller groups to accommodate post-season breaks and players involved in the knockout stages of domestic or European Cup competition.

The majority of players will then be given three weeks off and will return from mid-June to intensify pre-season preparations in Edinburgh.

There will be three pre-season residential camps in Scotland and a hot weather camp in Portugal before four home-and-away summer Test matches against Georgia and France in August.

"As it's likely to be hot and humid during the tournament, our warm-weather training camps in Portugal and Nagasaki, as well two Test matches in the heat of Nice and Tbilisi, should be invaluable," Townsend added.

Scotland training squad

Forwards

John Barclay (Edinburgh), Simon Berghan (Edinburgh), Jamie Bhatti (Glasgow Warriors), Magnus Bradbury (Edinburgh), Fraser Brown (Glasgow Warriors), Allan Dell (Edinburgh), Matt Fagerson (Glasgow Warriors), Zander Fagerson (Glasgow Warriors), Grant Gilchrist (Edinburgh), Gary Graham (Newcastle Falcons), Jonny Gray (Glasgow Warriors), Stuart McInally (Edinburgh), Willem Nel (Edinburgh), Gordon Reid (London Irish), Jamie Ritchie (Edinburgh), Sam Skinner (Exeter Chiefs), Grant Stewart (Glasgow Warriors), Josh Strauss (Sale Sharks), Blade Thomson (Scarlets), Ben Toolis (Edinburgh), George Turner (Glasgow Warriors), Hamish Watson (Edinburgh), Ryan Wilson (Glasgow Warriors).

Backs

Darcy Graham (Edinburgh), Nick Grigg (Glasgow Warriors), Chris Harris (Newcastle Falcons), Adam Hastings (Glasgow Warriors), Stuart Hogg (Glasgow Warriors), George Horne (Glasgow Warriors), Pete Horne (Glasgow Warriors), Rory Hutchinson (Northampton Saints), Huw Jones (Glasgow Warriors), Sam Johnson (Glasgow Warriors), Blair Kinghorn (Edinburgh), Greig Laidlaw (Clermont Auvergne), Sean Maitland (Saracens), Byron McGuigan (Sale Sharks), Ali Price (Glasgow Warriors), Henry Pyrgos (Edinburgh), Finn Russell (Racing 92), Tommy Seymour (Glasgow Warriors), Duncan Taylor (Saracens).