Wessels wouldn’t use the absence of leading forwards Luke Jones and Isi Naisarani as an excuse for the loss, and instead said he was unhappy with the way his side was directed in the second half.
The Rebels tied the game at 17-17 just minutes into the second half but went no closer.
“The first half we played quite well, with a lot of tempo, played in the right areas of the field and created some pressure,” Wessels said.
“In the second half we moved away from doing some of those things and gave the Bulls the type of possession they enjoy.
“They have an impressive forward pack that got a rumble on and they took the game.
“Those guys [Jones and Naisarani] are strong go-forward guys and we missed a bit of that but the pack we did pick stood up to a good Bulls pack.”
Playmakers Will Genia and Quade Cooper were targeted for some very physical treatment by the Bulls and they made no apologies for that.
“We know they attack very flat so we knew that if we put some heat on Genia and Cooper we will get some turnovers,” Bulls five-eighth Handre Pollard said.
“In Super Rugby that’s by far the best ball to attack from.”
Wessels said he would work with his playmakers to figure out how things went wrong.
“Where we lost the game was tactically in the second half, we played the type of rugby the Bulls wanted us to play which was silly,” Wessels said.
“We kicked a lot more proactively in the first half and moved their big forwards around, early on in the second half we got some pay for our running game and then over-used it. That allowed their forwards to get some energy and get back into the game.
“The pace of the game was very different in the two halves, there was some real tempo in the first half and the second half that went out of the game.”
The Rebels face the Sunwolves in Tokyo on Saturday and they will need the win and possibly gain the bonus point as well.
Jones (hairline eye-socket fracture) and Naisarani (big toe) won’t make the trip but Adam Coleman (shoulder) is expected to be available, as will outside back Tom English (calf). Both will travel although English still needs to prove his fitness.
Wessels won’t drop his head about the loss and said the Rebels still had a path to the finals, adding that the Bulls face the Brumbies next week so could also take points from them.
“It’s been a frustrating night for us but there is a lot of rugby still to be played this year,” Wessels said.
“Everyone has pulled up well and we don’t have any [more] injuries so we get to spend a little while together now when we head to Japan.”
The Rebels play the Sunwolves in Tokyo next Saturday at 3.15pm (AEST).
Roy Ward is a Sports writer for The Age.