Thiem has lost both of his prior matches against Raonic, who ended the dream run of lucky loser Miomir Kecmanovic, beating the 19-year-old Serbian 6-3, 6-4.
Raonic will face the victor of a match between No. 18 seed Gael Monfils of France and No. 7 seed Dominic Thiem of Austria in a semi-final.
"A lot of my injuries people think it was because I was lazy or not doing the job, and I always tell them that, you know, it's part of luck sometime", he said.
Germany's Kerber defeated seven-time Grand Slam champion Venus Williams 7-6 (7/3), 6-3. "I'm definitely playing how I feel it, and it's going well so I'm not planning on changing that".
Belinda Bencic upset fifth seed Karolina Pliskova 6-3 4-6 6-3 to reach the semi-finals of the women's event and ensure that she will return to the top 20 in the WTA rankings on Monday.
"I was really surprised", Thiem said, who was waiting to be taken to the court when he realized there was a problem".
"He's won his last three matches against good players", Raonic said.
When asked where a title this week would rank in his career, Raonic said, "It would be there, I believe, parallel to the Wimbledon final (in 2016), if not higher, just because it's going through a week amongst the best players in the world without sort of ending with a loss".
The Canadian recorded another break to open the second set, but Svitolina bounced back in the next game with her own break and then won three more games in a row to take charge.
Bencic won her third career title at Dubai last month and her first since 2015.
Bencic was pushed to three sets for the first time in four matches at the tournament.
The Swiss racked up 27 unforced errors in the match to just 14 winners, and Kerber converted seven of the nine break points she held, thanks in part to winning 65 percent of points played in Bencic's service games overall.
Bianca Andreescu of Mississauga advanced to the women's semis on Wednesday.
At 15-3 this year, Monfils was off to the best start of his career, but he was 0-4 against Thiem.
Naomi Osaka Thrashed By Belinda Bencic In Indian Wells 2019
Halep responded after losing the opening set, dropping just three service points to level the match in fine fashion. Venus Williams reached the quarterfinals with a 6-4, 6-4 win over Mona Barthel.