Christophe Berra admits some players used to "dread" international duty but the atmosphere within the Scotland squad has changed recently.

The defender could take the captain's armband in Thursday's 2018 World Cup qualifier at home to Slovakia in the absence of the injured Scott Brown.

But while he has been a mainstay in Gordon Strachan's squads over the last four years, Berra says it hasn't always been a happy group of players.

The feeling in the camp has significantly improved going into the closing stages of the Group F qualifiers though, after picking up 10 points out of the last 12 and keeping their dream of reaching Russia next summer alive.

"Training has been good and the boys are coming from clubs full of confidence," Berra said.

"I think people nowadays like coming away and working under the manager and playing for their national team, whereas maybe years back people dreaded it a little bit sometimes.

"There is a lot more optimism around the country and it's in our hands to hopefully keep that positive vibe going. The only way we can do that is by winning."

Scotland's campaign took a hit this time last year when they drew 1-1 with Lithuania at home before losing 3-0 to Slovakia in Trnava.

They closed the year with a 3-0 defeat away to the Auld Enemy in November but Berra says their form has dramatically improved.

"We've come off two good victories, a good point against England, which really should have been three points," the defender continued.

"We have improved since then, there have been a lot of changes as well. I say we have improved, but really we can only tell when the final whistle goes how much improvement there has been.

"You have got to be humble and don't get too carried away when things are going well, and when things are not going well, don't get too down."