The Bulls will have to make three injury-enforced changes for their Super Rugby encounter with the Western Force in Pretoria on Saturday.

The biggest blow has come in the form of an injury to Springbok Dewald Potgieter, who suffered a grade two medial ligament injury in the 25-17 win over the Stormers at Loftus Versfeld last Friday.

Bulls team doctor Org Strauss confirmed that Potgieter will be sidelined for three to four weeks and miss the team's overseas leg of the competition - with starts when they play the Blues in Auckland on Sunday, March 10.

The most likely replacement are Boks Jacques Potgieter, who was withdrawn from the encounter with the Stormers with a groin strain, and Arno Botha - who came on as a replacement late in the first half.

Other setbacks include JJ Engelbrecht (hip flexor, 10 day lay-off) and Bok flank Deon Stegmann (hamstring, 10 days).

Engelbrecht and Stegmann are also in doubt for the Australasian trip, but a call on their availability will be made later.

According to the Bulls doctor, Strauss, players like Werner Kruger (ankle) and Grant Hattingh (sick) will only train on Wednesday, but veteran wing Akona Ndungane and Jacques du Plessis will take the field at training on Monday.

Ndungane recovered from the ankle strain that ruled him out of the Stormers clash and SA Under-20 flank Du Plessis has recovered from an AC joint.

Wilhelm Steenkamp and Dean Greyling are on track to train with the team next week, after shoulder and foot injuries respectively that ruled them out of the encounter with the Stormers.

The two shining lights in the Blue Bulls pre-season win over the Free State this weekend, Jan Serfontein (quad) and Ulrich Beyers (ankle) will join the fray on Wednesday.

The one question mark still remains over Jacques Potgieter, who was withdrawn with a groin strain from the team to face the Stormers, but appears nowhere on the team injury list. Potgieter would be a perfect replacement for his namesake Dewald if fit, while Arno Botha would also come into the equation.

At centre, Francois Venter is likely to be the favourite to replace Engelbrecht, although Frans Ludeke also has the option of returning Lionel Mapoe to the midfield now that Ndungane is fit again. Jan Serfontein is also one whose name should come into play when midfield selections are made.