Jonny Gray, Adam Hastings, Ross Thompson and Glen Young have joined the Scotland squad before Saturday's Six Nations meeting with Italy in Rome.

Gregor Townsend's Scots won their opening match in this year's championship against England but lost to Wales and France.

Italy have lost to France, England and Ireland so far.

Lock Gray, 27, missed the 36-17 home defeat by the French in round three while fly-half/full-back Hastings, 25, is yet to feature in this year's Six Nations.

Fly-half Thompson won his only cap so far during the autumn series while lock Young is uncapped.

Scrum coach Pieter de Villiers said: "It's been fantastic to see that our depth has grown over this past two seasons.

"[Rome] is a very difficult place to play, a very passionate place in terms of energy and people behind their team.

"[Italy are] a very physical team. We need to take that battle up on the right side and get off to a good start against a team like that, who'll have a lot of physicality and emotion involved."

Scotland squad

Forwards: Ewan Ashman (Sale Sharks), Josh Bayliss (Bath), Simon Berghan (Glasgow Warriors), Magnus Bradbury (Edinburgh), Andy Christie (Saracens), Allan Dell (London Irish), Rory Darge (Glasgow Warriors, Matt Fagerson (Glasgow Warriors), Zander Fagerson (Glasgow Warriors), Grant Gilchrist (Edinburgh), Jonny Gray (Exeter Chiefs), Jamie Hodgson (Edinburgh), Stuart McInally (Edinburgh), Kiran McDonald (Glasgow Warriors), WP Nel (Edinburgh), Pierre Schoeman (Edinburgh), Sam Skinner (Exeter Chiefs), George Turner (Glasgow Warriors), Hamish Watson (Edinburgh), Glen Young (Edinburgh).

Backs: Mark Bennett (Edinburgh), Darcy Graham (Edinburgh), Chris Harris (Gloucester Rugby), Adam Hastings (Gloucester Rugby), Stuart Hogg (Exeter Chiefs), Rory Hutchinson (Northampton Saints), Sam Johnson (Glasgow Warriors), Blair Kinghorn (Edinburgh), James Lang (Edinburgh), Ali Price (Glasgow Warriors), Kyle Rowe (London Irish), Finn Russell (Racing 92), Kyle Steyn (Glasgow Warriors), Ross Thompson (Glasgow Warriors) Sione Tuipulotu (Glasgow Warriors), Duhan van der Merwe (Worcester Warriors), Ben Vellacott (Edinburgh), Ben White (London Irish).