Craig Gordon had no fears about Celtic team-mate Kieran Tierney lining up at right-back for Scotland. The 19-year-old left-back switched sides for the crucial World Cup qualifier against Slovenia and delivered his usual tenacious defensive performance and adventurous forays forward to help the Scots to a 1-0 victory.It was unfamiliar territory for the teenager in only his third international appearance but Gordon knew he had the temperament to adapt. Gordon said: "I had asked him when the last time he played there was and he said it was when he was playing boys' club football. But then I realised that wasn't that long ago, so I thought it would be all right."He is so young, he just takes everything in his stride. He isn't fazed by anything."He's just a really good player, I think you could play him anywhere and he would fight his corner and do a job for the team. He's a great team player so there's no problem with wherever you play him. "If he's out on the park he is going to give it 100 per cent and more often than not puts in a really good performance." Tierney was among six Celtic players who started for Scotland on Sunday with Stuart Armstrong winning man of the match on his debut and setting up Chris Martin's late winner. "He was outstanding," Gordon said of the midfielder. "He was the same all week in training, he was one of the best players in training, scoring goals. He is a real threat from that area, both goals and assists."When you've got a player like that on top form, it's just great to see him playing that well. He wasn't a regular in the Celtic team at the start of the season and he had a wee injury a few weeks back but he has just come back even stronger."To put in a performance like that on your first cap, it just shows how good a player he actually is. I'm looking forward to him scoring a few more and getting a few more assists before the end of the season."