Hendricks only bowled three overs in the second unofficial test between South Africa A and India A before he was whipped off the field as a precautionary measure due to a back ailment.
The exact nature of the injury is yet to be determined. Hendricks is on holiday in the Seychelles and Shane Jabaar, the Cape Cobras physiotherapist, will assess him upon his return.
Hendricks was side-lined for several months in 2014 due to a stress fracture of his back after making his T20-debut for South Africa earlier in 2014 and featuring in five games at the ICC Twenty20 World Cup.
The fast bowler nipped out 28 batsmen in the Ram Slam T20 Challenge in 2013/2014-season. Following an encouraging performance for the Cape Cobras in the final Sunfoil Series match of the 2014/2015-season, he was selected for the South African T20-squad to Bangladesh.
The latest setback can curtail the progress of the left-arm swing bowler.
Parnell (26) has taken 110 wickets in 85 international games for South Africa, but he had to pull out of the WP-squad for the Africa T20 Cup due to a hamstring problem.
His progress is monitored by Jabaar.
The Cape Cobras management team has decided to withdraw Justin Ontong from the Boland squad for the Africa T20 Cup. He is still on the mend following knee cartilage surgery, and his rehabilitation process is not completed.
Paul Adams, the Cape Cobras coach, said the withdrawal is a precautionary measure to ensure Ontong, a former SA captain, is ready for the season.