Robert Snodgrass and Steven Naismith return to the Scotland squad for the home Euro 2020 qualifiers with Russia and Belgium.
Defenders Grant Hanley and Liam Cooper are also called up by manager Steve Clarke, with Scott McKenna among those missing through injury.
Portsmouth keeper Craig MacGillivray is included for the first time.
The 29-year-old has three goals from eight appearances this season after taking six months out of the last campaign to deal with personal issues.
The centre forward, who has scored four goals in his past seven internationals, played and scored in a Reserve Cup match on Monday.
“He’s come a long way in a short space of time after a very difficult spell in his life,” said Clarke. “I feel we should just give him a little more time to settle into the role again at Celtic and get himself fully fit and firing. And a fully fit and firing, sharp Leigh Griffiths will always be good for us.”
The experienced Steven Fletcher is also absent, despite being a regular starter for Sheffield Wednesday this term, while Oli McBurnie is back, along with forwards Matt Phillips and Naismith, who has yet to manage more than 45 minutes in two outings for Hearts this season.
Naismith, 32, who has 49 caps, scored twice in four games when returning to the Scotland fold in late 2018 after 18 months out in the cold.
Snodgrass, who has started once for West Ham this season, has not featured for Scotland since a friendly loss to Belgium last September but Clarke said the 31-year-old was “very keen” to resume playing after his recent hiatus.
Rangers’ Ryan Jack and Ryan Christie of Celtic are among the midfield options, with Tom Cairney and Graeme Shinnie dropping out.
Forwards Oliver Burke, Marc McNulty, Eamonn Brophy and LeWIS Morgan are also missing from the first squad Clarke named when he succeeded Alex McLeish two games into a faltering campaign. Goalkeeper Liam Kelly and defender Stuart Findlay are cut too.
McKenna is joined by Aberdeen team-mate Michael Devlin and Hearts’ John Souttar on the list of injured centre-halves, with Hanley, who has not played for Scotland since a 1-0 loss to Costa Rica in March 2018, coming in along with the uncapped Cooper.
With Scott Bain adding to a long list of injury absentees, Perth-born MacGillivray is preferred to Kelly, who has not started a league match since his move to QPR.
Scotland, fourth in qualifying Group I with six points from four games, host the Russians on 6 September, before welcoming the Belgians three days later.
Scotland last faced Russia in the successful qualification campaign for Euro 96, drawing home and away. Belgium, ranked the number one team in the world, beat Scotland 3-0 in Brussels in June and top the group with maximum points.
Goalkeepers: Craig MacGillivray (Portsmouth), David Marshall (Wigan), Jon McLaughlin (Sunderland)
Defenders: Liam Cooper (Leeds United), Grant Hanley (Norwich), Charlie Mulgrew (Wigan), Stephen O’Donnell (Kilmarnock), Liam Palmer (Sheffield Wednesday), Andrew Robertson (Liverpool), Greg Taylor (Kilmarnock)
Midfielders: Stuart Armstrong (Southampton), Ryan Christie (Celtic), Ryan Jack (Rangers), John McGinn (Aston Villa), Callum McGregor (Celtic), Kenny McLean (Norwich City), Robert Snodgrass (West Ham), Scott McTominay (Manchester United)