Steve Clarke admits he is frustrated he still cannot select Kieran Tierney for Scotland.

The left-back has not been included in Scotland's squad for their final two European Championship qualifiers against Cyprus and Kazakhstan this month.

Tierney has not played for Scotland since the 2-1 defeat in Israel in October 2018 after experiencing long-term pelvic problems which saw him undergo double hernia surgery in the summer.

The 22-year-old has now played six games for Arsenal since making his £25million move from Celtic but his comeback has been phased and Clarke is still waiting to select him for the first time.

Clarke, whose only communication with Arsenal came via written forms, said: "Kieran has got an ongoing issue that Arsenal are keen to address in the next international break and Arsenal asked us not to select him.

"It's a little bit frustrating. It's obviously frustrating for Kieran as well, but we've got good cover in that position."

However, the Scotland manager is learning not to get exasperated about selection issues.

"There are always issues when it comes to squad selection, people in the squad and not in the squad," he said. "I'm learning on the job and not to read too much into squad selection, team selection, not to think about it too much until you have actually got the players in camp.

"I have to focus on the players that come. My job is to try and build a squad that comes 100 per cent committed, everyone committed ready to come here and do their best for their country, and that's what I am trying to do."

Clarke has lost centre-backs Charlie Mulgrew and Stuart Findlay to hamstring injuries while Sporting Kansas City attacker Johnny Russell is unavailable after picking up a minor injury just before the end of the American season.

Robert Snodgrass is another player to drop out of the previous squad after announcing his international retirement. The winger played in the 4-0 defeat by Russia last month but left the squad before the victory over San Marino.

When asked if the news of his retirement came as a surprise, Clarke said: "Not really because I have had a few conversations with Robert before he came back into the squad and I know where his thoughts are.

"He phoned me the night before he announced his decision to retire, we had a good conversation and wished each other well and we have to move on.

"Nothing happened, Robert just decided he wanted to focus on his club career. He wants to play more often for West Ham and he decided the best way to do that would be to retire from international football, so we wished him well."

When asked about claims Clarke was not going to pick Snodgrass anyway, the Scotland boss said: "It doesn't really matter because he has retired. There's nothing really to discuss, Robert made the decision to retire and we wish him well."

Defenders Scott McKenna and Liam Cooper return after injury while Ryan Jack and Oli McBurnie are selected after withdrawing from the last squad through injury.

And Steven Naismith is back in the fold after being ruled out with knee and hamstring injuries over the last 12 months, even though he has only made one substitute appearance for Hearts since recovering from the muscle problem.

"He hasn't had much game time but he's a good professional, Steven," said Clarke, who is looking to finish third to boost confidence ahead of the March play-offs.

"I had a good conversation with him on Monday. He assures me his fitness is good, he has been working hard on it.

"He obviously got some minutes on the pitch in the semi-final at the weekend and he expects to start their next game. So hopefully he can add something to the squad."