Sebastian Vettel admits he isn't quite sure what to make of Robert Kubica's sensational comeback attempt.
The Polish driver, whose F1 career suddenly ground to a halt in 2011 following a rally accident, is believed to be Williams' elected choice to partner Lance Stroll next season.
Kubica recently undertook a series of tests with the Grove-based outfit, the last of which were last week in Abu Dhabi and deemed successful.
Vettel however is perplexed by his former rival's F1 endeavors.
"I think it's very tragic what happened back then," Vettel told Sonntagsblick newspaper.
"He was regarded as a future champion. But I do not understand why he is pushing for a comeback now. Why did he not do this before?
"For him it would be a nice story, but on the other hand it would be unfortunate for younger drivers who would also like that cockpit," Vettel said.
Renault's Nico Hulkenberg agrees that Kubica's return would be a "huge story" for F1.
"In testing you can see that the pace is there," he told Sport1.
"But you cannot simulate the racing action of the first lap in Monaco or Singapore," Hulkenberg said.
"I hope he is able to race at the highest level, but we will only see that when he's in the car next year. I estimate the chances of his comeback at 50-50," the Renault driver added.