The world number one was in imperious form yesterday, dismantling 22nd seed Jeremy Chardy in straight sets on Centre Court.
The victory, his seventh against the Frenchman, sets up a last-16 clash with 13th seed Haas.
The German might be in the twilight of his career at 35, but his form has been impressive this year - something Djokovic knows all too well.
While the Serbian may have won their quarter-final clash at the French Open, Haas came out on top at the Miami Masters in March.
"Against Tommy Haas, it's going to be a big challenge for both of us," Djokovic said.
"I think it's his most preferred surface. He loves playing on grass.
"He had a few great wins lately. He beat Roger in the finals of Halle last year.
"He played again really well this season on grass. In general, this season he played great.
"I mean, he's 35, 36 years old, and he's been playing very close to the best tennis of his life, in my opinion.
"He's very fit. He doesn't look like 35 years old man, for sure. He's full of confidence on the court.
"Look, there's no clear favourite in that match. I need to try to repeat the performance from today.
"If I do so, if I feel this well, I think I have a good chance."
The victor of that clash will face Bernard Tomic or world number six Tomas Berdych in the quarter-finals.
The other ties in that half of the draw see fourth seed David Ferrer take on Ivan Dodig and Andreas Seppi face Juan Martin Del Potro.
Most of the home interest on Monday will focus on Andy Murray, who takes on in-form Mikhail Youzhny after the Russian came through yesterday's clash with Viktor Troicki.
"I think everybody knows him and knows how he plays," Youzhny said of Murray.
"He plays really well on the grass.
"I have not played so many matches against him. It will be really tough match for me. He is a really tough opponent.
"I need to be just ready to play and enjoy the Centre Court, because not every year you can play against top players on the Centre Court. It will be a nice atmosphere against a good player."
Monday promises to be a fine day of tennis and British fans will be keeping half an eye on the clash between Fernando Verdasco and Kenny De Schepper, with the winner facing Murray should he overcame Youzhny.
In the semi-finals, the highest-ranked player the Briton could face is Jerzy Janowicz.
The Polish 24th seed takes on Austria's Jurgen Melzer on Monday, with the winner facing either Lukasz Kubot or Adrian Mannarino in the quarter-finals.