VIDEO: Long way to go for 'robust' Bulls
VIDEO: Long way to go for 'robust' BullsSHARE
Mitchell has been shaking things up since his arrival in Pretoria last year in a bid to turn the Bulls back into a rugby powerhouse.
The Bulls were Super Rugby champions in 2007, 2009 and 2010. However, they have been in a steady decline over the last few years.
"We still got a long way to go," Mitchell told reporters in Pretoria.
"We built some solid foundations, we've tried a different approach and we think our athletes are really healthy. We think they have become more robust.
"We worked heavily on our individual skill sets and there is a great attitude amongst the group."
Mitchell added: "I think we selected some really quality men in this group who are really keen to become cohesive and connected.
"Obviously pressure will challenge us as well and the trials will challenge us, which we need. We need to be put under stress over the next four weeks before we go into the competition."
Bulls co-captain Burger Odendaal believes last year's Currie Cup tournament has prepared some of the Union's young talent for the rigours of Super Rugby.
"I think the Currie Cup was a good stepping stone for us and I think it was vital for a couple of the young guys getting the opportunity to play – now they are first in line, so they have to play against the big guns this year.
"I think the guys are really looking forward to it," said Odendaal.
The Bulls start their Super Rugby campaign against the Hurricanes in Pretoria on February 24.