Scotland boss Steve Clarke stressed the importance of being open-minded after including Dundee United striker Lawrence Shankland in his squad for the Euro 2020 qualifiers against Russia and San Marino.

Shankland is the Ladbrokes Championship's top scorer after netting 13 goals in seven league games for the club he joined from Ayr in the summer.

And Clarke has rewarded the 24-year-old's fine form with a place in a 25-man party which also includes uncapped Sheffield United midfielder John Fleck.

Prolific marksman Shankland follows in the footsteps of Aston Villa midfielder John McGinn, who was also plying his trade in Scotland's second tier – at Hibernian – when he received his maiden international call-up in 2016.

Clarke believes it is a deserved call-up for Shankland, who replaces injured Hearts man Steven Naismith in the squad for the trip to Russia on October 10 and the home clash against San Marino three days later.

He said: "I think you always have to be open-minded. You have to be prepared to try one or two different things.

"But it's also important as well that I keep faith with the players that I've got. I believe they're better than they've shown recently and I believe over the coming games they'll show that to the public as well.

"I know Lawrence quite well from my time here in Scotland, having watched him a few times, and it's not an area that we are over-burdened with – top strikers – at the moment.

"Lawrence is in form and he deserves his chance. The best way to look at him and gauge what level he is at is to bring him into the squad.

"It's an opportunity to have him in the group, see how he works in the squad and hopefully he can score a few goals for us.

"He's a natural finisher and that's something maybe we haven't had in the squad recently. So hopefully this will address that."

There was no place in Clarke's squad for midfielder Stuart Armstrong, who has only featured as a substitute for Southampton so far this season, with Premier League regular Fleck coming in to take his place.

West Brom winger Matt Phillips is also absent as he will undergo a minor surgical procedure during the international break.

"I had a good chat with Stuart on the phone over the last 24 hours and, although he's disappointed to be out the squad, I think he understands where we're coming from," said Clarke.

There is a recall for Alaves loanee Oliver Burke, who came off the bench to score the late winner against Cyprus in June but was left out of Clarke's last squad.

He is joined in the fold by Rangers man Ryan Jack, whose club manager Steven Gerrard said Scotland had been careless with the midfielder's fitness during the last international break.

Meanwhile, left-back Kieran Tierney has not been picked after only making his debut for new club Arsenal last week following a lengthy spell on the sidelines.

Clarke said Arsenal were keen for Scotland to omit Tierney from their squad on this occasion.

"I was close to selecting Kieran," he added. "Arsenal have indicated to us that they would prefer us not to select him at this moment in time because he has only played 70-odd minutes of football. You have to respect the club's decision on that one."