"We had a very good honesty session with the players on Monday and I showed them the replay of the driving maul try, which was the most embarrassing moment in the game" said Rowntree.
"That simply can't happen again - we have to fix that this week. It was a technical issue and it was something that came back to bite us on the backside again after we hadn't handled it very well in the opening game.
"We have to be better technically and have a better collective spirit when we are defending the driving maul. We will handle it much better this weekend."
As well as conceding that try to Heinrich Brussow from a driving line-out, the Lions' scrum conceded nine points from three penalties in the first-half. As Rowntree admitted, that left the tourists with a mountain to climb.
But the Lions' 'scrum doctor' is confident that the Lions' scrum can be sured up for the whole game at LoftusVersfeld and isn't ruling out a number of changes in the pack ahead of the must-win second Test.
"The guys who came on for us in the second half last weekend made a significant difference. There could well be changes in all three rows of the scrum ahead of Saturday," admitted Rowntree.
"We have got to fix up our set piece and I'm confident we can do that. We need a couple of good training sessions this week and we have looked at what happened last weekend collectively."
The Lions coaching team sits down to select the team for the second test on Wednesday afternoon and will announce the side on Thursday.