Celtic striker Leigh Griffiths is in the squad while Wigan Athletic pair Gary Caldwell and Shaun Maloney are back following injury lay-offs. Former Dundee left-back Forsyth and Suffolk-born forward Martin have helped Derby into the English Championship play-off final.
Manager Gordon Strachan said of Forsyth: "I think he has played every game this year. If you get picked by Steve McClaren every game then there should be a chance you get picked by me. He has done very well, like Andy Robertson, to go away and discover himself and find out exactly what he can do and take a few knocks along the way and come back a very good player for a very good side."
Former Norwich player Martin, 25, qualifies for Scotland through his father. Strachan said: "Chris Martin would have been in the squad the last time, unfortunately we couldn't get the clearance from FIFA in time, but we kept Chris up to speed. He was disappointed he couldn't make it, but so excited this time. He's got a physical presence but he's a footballer. He's not the quickest but he has a quick mind."
Norwich pair Robert Snodgrass and Russell Martin have been left out for fitness reasons after playing through the pain barrier in their unsuccessful bid to keep the Canaries in the Barclays Premier League.
Stoke midfielder Charlie Adam has been left out to allow Strachan to look at the likes of the recalled Graham Dorrans, James McArthur and George Boyd. Rangers player Cammy Bell is among four goalkeepers in the squad, along with Hull's Allan McGregor, who has just recovered from a serious blow to the kidney.
James Forrest and Steven Fletcher are among those who are unavailable through injury, while Strachan resisted the temptation to promote the likes of Stevie May and Stuart Armstrong as Scotland Under-21s have a European qualifier against Holland on the same night as the full team's Craven Cottage encounter against Nigeria.