The Edinburgh back has been a key component of a Dark Blue attack that leads the way in terms of championship tries so far.
The Scots notched up two touchdowns in their opening-day defeat to England before running in another four in their 34-10 success over Italy last time out. But both games gave cause for concern at the breakdown as Scotland struggled to develop quick ball to their pacy runners.
Now Visser has urged his team-mates to stiffen their resolve in the tackle if they are to mount a Six Nations title challenge. He said: "It's a vast improvement from where we have been in the past in terms of finishing but it is disguising where we are as a team.
"We need to look at the fundamentals of our game and look at the tackle contests, our defence and our breakdown. Those are all important areas we need to improve on."