"I thought we set the bar fairly high on Saturday in difficult conditions," said Rowntree.
"A lot of our proven guys that have played a lot of games found those conditions harder than anything, harder than altitude or anything like that.
"We were delighted with the way things went. They had a great work out and they've got that in the bag.
"In difficult conditions and our first hit-out together, the guys set a high standard and tomorrow night's crew have got to move that bar up again.
"We've said to the guys that in the first three games everyone gets a start, so after the Reds game next Saturday I think we have got to start making some decisions on combinations and having a look at people.
"And certainly by the Waratahs and Brumbies games, we need to know who we are going to start with in the first Test, but at this point in time there is everything there to play for for everyone."
Rowntree expects a stern test from former playing foe Michael Foley's troops at Paterson Stadium, even if the Super XV outfit are without a few of their front-line names.
Foley has still included a host of Wallabies in his starting line up and Rowntree knows there is more than enough quality within the opposition to make life difficult for The Lions.
"It's not a bad team. There are not a lot of guys there who have played a lot of Super Rugby, but it still looks a strong enough team for me," added Rowntree, who insists that the major focus will be on The Lions' own performance in game number two.
"There has been a lot of local chat about how they want to play this game, how physical they want to make this game, and we've got to meet that challenge, whoever is on the field.
"We need to get our performance as good as it can be. You have got to take your chance on this tour - there is lots of competition.
"We are very respectful of the opposition but we are wary of getting our detail right and our structures up and running. This is another starting XV for us and we've got to get our combinations going. It's about getting those things in place.
"I think we have got a great group of players. With all due respect to previous Lions tours, we've got an exceptional group of players and it is about time we delivered."