The Bulls' leaky defence continues to be a problem after their 14-38 defeat to the Blues in Albany on Saturday.
After a 7-all score at the break, the floodgates opened in the second half with the Blues scoring five tries to secure a bonus-point win.
"If you concede so many tries in the second half and in every match then defence is definitely a concern," said Bulls coach Nollis Marais.
"That [defence] is something we will need to revisit and have a look at."
Marais believes his team played into the Blues' hands in the second half.
"I think we were very competitive in the first half.
"We did not take our chances in the second half like we were supposed to do and we gave the Blues too many opportunities to score.
"However, we had a great scrum. I thought it was an excellent scrum performance by Trevor [Nyakane] and we were dominant in the scrum, so that's a very good positive," Marais added.
The loss was the Bulls' third in four matches this season and they are currently 12 points behind leaders Stormers in the Africa Conference One standings.
The Pretoria side travels to Hamilton next to face the Chiefs. They then travel to Tokyo to take on the Sunwolves.
For more rugby news, visit Rugby365.com