The season's penultimate round ends on Sunday and Rovanpera will retain the title if he matches or scores more points than Evans, who misjudged a corner on the 11th Muhltal stage and slid into a barn door.
The car was too damaged to continue but Toyota said Evans, more than 40 minutes adrift and in 37th place, would be able to return on Sunday and attempt to score bonus points in the final stage.
"We would have liked to see their fight continue like it was through to the end of the rally, but of course, it is not completely over yet," said Toyota team principal Jari-Matti Latvala.
"The team could fix Elfyn’s car so he can still do whatever he can on the Power Stage to keep the battle alive.
"At the same time, we know Kalle is in a good position now and that he has the ability to manage the situation."
Overnight leader Rovanpera was in second place after Saturday's leg and 26.2 seconds behind Hyundai's Thierry Neuville, with M-Sport Ford's Ott Tanak more than a minute behind him in third.
"I knew that Elfyn was off, so why would I risk anything anymore?" said the Finn.
"Now the goal is a bit different and we will just try to finish with some good points."
Sunday sees a further four stages in the rally on roads in the Czech Republic, Austria and Germany.
