Waratahs captain Dave Dennis has warned his team-mates that there can be no room for complacency against the Lions after they beat the Hurricanes with a bonus point in their last outing.
The Waratahs had a bye last week and as they were not playing they have dropped out of the top six and will drop further behind if they lose to the Lions.
The Sydney side have not won back to back matches for 10 weeks and have alternated wins and losses since the third round.
"We've obviously had that run of win, loss, win, loss for the last couple of weeks and it is something we've talked about: putting that win, win back to back," Dennis told AAP.
The Lions are down in 11th place and are almost certainly out of the play-offs but could spoil other team's chances with upset wins.
Dennis said that the Waratahs of days gone by would have "would have taken them a bit easy".
However the 2014 Waratahs are determined to build a winning culture and having watched the Lions come from 23-0 down to lose by a point Dennis said that they will be taking the Lions seriously.
The match came down to a conversion kick which was missed by flyhalf Elton Jantjies.
"They should have won that match," Dennis said.
"Seeing what they've done over previous weeks definitely gives you an insight into what they're capable of. They're a strong attacking team."
The Lions are third in the South African Conference having won four out of 11 matches so far.
"Probably teams might have underestimated them a bit in terms of what they're capable of," Dennis told AAP.
"They're nice and physical, they've got some strong ball carriers, they play quite wide and they can score points.
"So we're expecting a physical game to start with - most South African teams are physical - and also that threat of having to defend the whole field is going to be a good challenge for our defensive system.
"Obviously in our last outing, we let ourselves down in that area, conceding 30 points against the Hurricanes so it's something we've got to be better at."
The match is on Sunday this week and the Waratahs will have to watch for a slow start as they will be going 15 days between matches,
"You can look at the break and say it's too much and people could say you've had too much time off and your head's elsewhere," Dennis said.
"Or you can say it's been an opportunity to freshen up. It's been a tough slog for a while.
"We're in a good position. There'll be no excuses come Sunday not to put in a really good performance.
"You can come up with excuses why we haven't had that consistency yet and Sunday is a good opportunity to find it."
Waratahs coach Michael Cheika has delayed naming his team to play the Lions as he wants to give lock Jacques Potgieter more time to recover from a lower-leg injury.
Dennis did however say that Potgieter has "just got a bit of bone bruising" and should be available to play.