De Silva picked up the injury while batting on Day 1 of the Boxing Day Test in Centurion.
De Silva batted commendably for his knock of 79 on Day 1 of the Boxing Day Test in Centurion before being observed in severe pain after taking a single.
Read Also: Sri Lanka’s pace attack on par with South Africa, says Dimuth Karunaratne
He had to retire hurt and was replaced by teammate Niroshan Dickwella at the crease.
Sri Lanka Cricket (SLC) informed in a statement that the right-hander won't be able to play for "about 2 weeks".
"Batsman Dhananjaya de Silva, who suffered a Thigh Strain, while batting in the 01st Test Match vs South Africa, will not be able to play for about 02 weeks. The player has sustained a grade 2 tear on his thigh," SLC tweeted.
No.4 Dinesh Chandimal, along with whom De Silva shared a crucial stand and helped Sri Lanka recover from a precarious situation, provided further update on his partner's injury.
"Straight after his injury, he said to me that it was a strain. He's going to the MRI [scan] now," Chandimal had told host broadcasters 'SuperSport', as reported by ESPNcricinfo.
"He thinks he can't play for two to three weeks. So that is the thinking, anyway. We'll see how the MRI goes, and hopefully, he'll recover soon. He batted outstandingly, really well, so credit goes to him as well," he added.
Sri Lanka were 54/3 when De Silva joined Chandimal and they batted superbly to take the side near the 200-mark.
Unfortunately, Silva had to limp his way back to the pavilion prematurely because of his injury, but Chandimal then found another able ally in Dickwella.
They put on a further 99 runs for the fourth wicket before Chandimal was dismissed following a well-made 85. Dickwella himself ended with a vital 49 as the touring team finished play in a position of strength at 340/6.