Boss Gordon Strachan hailed James McArthur's mental strength after he recovered from a shaky start to score Scotland's third goal in the 3-0 win over Lithuania on Friday nightThe 29-year-old midfielder was off the pace in the early stages of the crunch World Cup qualifier at the LFF stadionas in Vilnius and one mistake at 0-0 led to a good opportunity for former Hearts attacker Arvydas Novikovas, but he missed the target from 12 yards.However, it was the impressive Scots who got the breakthrough when Celtic midfielder Stuart Armstrong scored his first goal in dark blue with a header from a Leigh Griffiths corner in the 25th minute. Liverpool new boy Andy Robertson curled in a glorious second five minutes later before McArthur added a third from close range in the 72nd minute to clinch three valuable Group F points.Strachan praised Armstrong's contribution on only his third Scotland appearance before highlighting McArthur's display. He said: "I thought one of the stand-out performers was James McArthur because in the first 15 minutes you think, 'Oh!' "And to come back from that to play as well as he did is mental strength."We all take for granted how well Scott Brown and Matt Phillips played, but to start maybe not that great and to come back.I think his mates looked after him at that point and he gave it back and because of that he scores a goal."After seven Group F fixtures, Strachan's men have 11 points, still four behind second place Slovakia, who beat Slovenia 1-0The Scots moved into third place above Slovenia and face minnows Malta at Hampden Park on Monday before hosting Slovakia and travelling to take on Slovenia in what will be two tense games in October.Strachan was pleased to be able to enjoy the latter stages of the game.He said: "I am really pleased, t he fact that at one point I could become a spectator to enjoy the football. "It is not often you can do that as a manager, but that was the performance that allowed us to do that."The team were excellent."