Du Plessis has a wound on his right hand which he picked up during the 23-19 victory over Wales on Saturday.
Coach Heyneke Meyer could also be without De Jager after he suffered a foot problem against Warren Gatland's men at Twickenham.
The South African medical team are apparently willing to wait a few days to give them time to recover, but Meyer will be able to call up second row Victor Matfield.
"Bismarck has a nasty laceration to his right hand. Francois Louw accidentally stood on his hand," team doctor Craig Roberts said.
"Luckily there's no fracture but it is a bit sore and swollen for him, so we will keep an eye on him throughout the week. Lood has injured a tendon in his foot so we need to give him some time to see how that settles and we will make a decision later in the week on his availability for the All Blacks game.
"Victor has been doing really well with his rehab. He has been working really hard and progressing nicely but we will have to see nearer the end of the week."