The Boks have an unassailable 2-0 series lead following a 36-27 win at Ellis Park at the weekend.

Pietersen joined the squad in Port Elizabeth yesterday as fullback cover with Pat Lambie and Zane Kirchner doubtful starters this weekend.

Lambie has an ankle problem and Kirchner is battling to shake off a knee injury. Frans Steyn, who could have played fullback, is not available because he is getting married on Saturday.

Should Lambie and Kirchner both be ruled out, the No15 jersey for the dead rubber could be a straight shootout between Stormers teammates Pietersen and Gio Aplon, the latter called into the squad last week as cover for Kirchner.

The pair play together for the Cape-based Super 15 team with Aplon usually on the wing.

However, Aplon has played test rugby at fullback, has 16 caps and would be the favourite to start if it came down to a choice between the two players.

"Joe has always been part of our plans and also attended our final planning camp in Durban shortly before the England series started," Meyer said.

England captain Chris Robshaw became the latest injury victim for the tourists after being forced to withdraw from Saturday's test with a cracked thumb. He will be replaced by hooker Dylan Hartley.