"From the experience that we learnt from four years ago, it's all about preparing for the Test matches so the harder the games are the better prepared we're going to be," said Gatland.
"If Robbie will let as many of the Wallabies play in those warm up games, that will help us prepare.
"We found in South Africa we were undefeated in the warm-up games but, because there wasn't a lot of the South African players playing, we weren't tested as well as we could have been."
The Australian Super sides will break from their competition between June 9 and July 12 to allow for the Lions tour.
Friends since their playing days in New Zealand, Gatland was hoping to catch up with Deans for a beer before his reconnaissance mission ended.
He again defended the record of Deans, who endured a difficult season in 2012 as the Wallabies failed to placate critics with some gutsy results, including a draw with the All Blacks and second place in the Rugby Championship, as they averaged just one try a game.
Gatland believed the coach had done an excellent job in the face of the massive injury toll which now gave them much more depth.
"I said to him after the last game we were involved in, with Wales and Australia, 'You're killing me at the moment, winning in the last minute'.
"The unfortunate thing for Australia is probably not beating New Zealand as regularly as they would like and that puts him under a huge amount of pressure."