Owen Farrell will line up for Saracens in their Investec Champions Cup curtain raiser, which will be his first appearance since he announced he was taking a break from England duty.
The England captain has made himself unavailable for Six Nations selection after he chose to take a break from international rugby to prioritise his and his family's mental well-being.
He missed last week's game against Northampton Saints due to a knee problem.
However, Saracens' Director of Rugby Mark McCall has confirmed that the fly-half will be fit to face the Bulls in Pretoria on Saturday.
"He's available and he is going to play this weekend," McCall said. "He has trained fully over the last two days.
"He has enjoyed being with his team-mates, and it is a great opportunity for us all to spend a bit of time together away from the British winter.
"I don't know how many European Cup games he has played – him and Alex Goode have probably played in more than anybody at the club.
"He is our captain, he is our leader, someone who is respected by everyone at the club. To have him on the field, of course, is an enormous benefit.
"Not just to have him on the field, but have him in the team-room, in the meetings… His contribution is so enormous and it is great to have him here with us."
Three-time European champions Saracens have won the tournament more than any other English club, although they made a quarter-final exit last term to eventual winners La Rochelle.
And they will tackle a Bulls side currently third in the United Rugby Championship, having won five out of seven league fixtures this season.
McCall added: "We have been really impressed with what we have seen, especially in their last couple of home games. They are strong in all areas.
"Games don't get much tougher in round one than coming to the Bulls, especially with the run of form they are on, but it is a challenge which usually brings the best out of the group we have got.
"We've had a good relationship with this competition for a very long period of time. It has felt really good on the training field from the moment we touched down here."
