Jurgen Visser, Ulrich Beyers and Rudy Paige will all earn starts. It will be a first start of the season for scrumhalf Paige.
The trio replace Clayton Blommetjies, Johann Sadie and Ruan Snyman respectively, and while the first two are rested due to niggles, Snyman will play off the bench.
"We are certainly up against it," Pienaar said on Wednesday.
"To prop up the log at this stage of the competition is not great and does not reflect the hard work we have put in.
"The reality is that we are playing against ourselves as well at the moment and are making too many errors at crucial times and aspects of the game.
"We have to work harder and play smarter and that is what we intend to do on the weekend."
Blue Bulls captain Dewald Potgieter admitted a new mindset was required after losing three of their first five matches to leave them bottom of the standings.
"This is all about getting to the first objective of the season, and that is to make the playoffs and put ourselves in a position to win the Currie Cup again," Potgieter said.
"Looking at our efforts so far, we are not on track, so it will take a special effort from all to get there.
"Everyone needs to up their game and I am confident that we will see the work done on the training ground bearing fruit against Griquas, who will be very focused on beating us."
Teams:Griquas:
15 Willie le Roux, 14 Richard Lawson, 13 Jean Stemmet, 12 Walter Venter, 11 Rocco Jansen, 10 Francois Brummer, 9 Marnus Hugo, 8 Leon Karemaker, 7 Wesley Wilkins (captain), 6 Marnus Schoeman, 5 Martin Muller, 4 Ligtoring Landman, 3 Lourens Adriaanse, 2 Matt Dobson, 1 Steph Roberts
Substitutes: 16 Simon Westraadt, 17 Ivann Espag, 18 Frikkie Spies, 19 Justin Downey, 20 Jacques Coetzee, 21 Marnitz Boshoff, 22 Wilmaure Louw
Blue Bulls:
15 Jürgen Visser, 14 Akona Ndungane, 13 Ulrich Beyers, 12 Francois Venter, 11 JJ Engelbrecht, 10 Louis Fouchè, 9 Rudy Paige, 8 Dewald Potgieter (captain), 7 CJ Stander, 6 Warwick Tecklenburg, 5 Grant Hattingh, 4 Wilhelm Steenkamp, 3 Werner Kruger, 2 Willie Wepener, 1 Dawie Steyn
Substitutes: 16 Bongi Mbonambi, 17 Frik Kirsten, 18 Cornell Hess, 19 Jean Cook, 20 Ruan Snyman, 21 Lionel Cronjè, 22 Jan Serfontein