Rory Lawson insists he is not taking a place in Scotland's World Cup squad for granted, despite being named captain for Saturday's Test against Ireland.
The scrum-half has never lost as skipper, taking charge of November's wins over South Africa and Samoa.
Head coach Andy Robinson will name his final squad on 22 August, but Lawson says there is no room for complacency.
"I don't think any member of the squad would be sitting back thinking they're on the plane," said Lawson.
With British & Irish Lions Mike Blair, Chris Cusiter and Edinburgh's Greig Laidlaw, who can also play fly-half, vying for the number nine slots in New Zealand, the Gloucester ace is hoping to make Robinson's squad.
"I think the competition in the squad is better than ever," said Lawson.
"We've got 38 guys who are almost fully fit now, and as a result we've got 38 guys fighting for a spot not only in the 30 or the 22 but in the starting XV.
"Opportunities are at a premium and the competition for the scrum-half berth is massive.
"I'm being given the first opportunity to start, but I'm fully aware of the competition.
"It's ruthless and it's a challenge every day to make sure I'm performing well and giving myself the best opportunity.
"Other people make the decisions, but I've got to know I'm performing as best I can to put myself in a strong position."
Scotland's players returned from St Andrews to Edinburgh on Wednesday for final match preparations, with Lawson eager to extend his success as skipper.
"The game on Saturday is a huge match for us as a stepping stone towards the World Cup," he added.
"It's a full-blown Test match against one of the top teams in the world and we certainly want to put in a good performance after a lot of hard work so far this pre-season.
"I've really enjoyed the occasions on which I've captained Scotland.
"I don't see my role changing hugely as captain, but certainly leading the team out is something I'm incredibly proud of."
Head coach Robinson revealed on Tuesday he has chosen his World Cup captain, but he has yet to inform the players of his decision.
Lawson, who takes over the captaincy from Six Nations skipper Alastair Kellock, says he would be honoured to be given the role, but is not looking too far ahead.
"It would be massive, but for me just now my focus is on Saturday."