Livewire Smith, 24, will make his 27th Test appearance in Lille on Saturday after only having played at fly-half for England and his club Harlequins.
"I'm sick about answering questions about Marcus. The kid could play anywhere," Care jokingly told reporters.
"Whisper it quietly he could even play nine, but I don't want to get myself out of a position.
"I can't wait to see him light up the world stage, which I've known he's been able to do for a few years now," Care added about his England and Quins teammate.
England, winners in 2003, top Pool D after clinical victories over Argentina and Japan but have been criticised for a lack of creativity so far in the World Cup.
"What a great running game he's got," defence coach Kevin Sinfield told reporters.
"It lends itself to having more space and time, which you can often find yourself in as a full-back.
"We feel having someone like that in our team as a second ball player is a great addition and give us some more variety," he added.
Inside Smith in Lille will be Owen Farrell, who is captaining the side at fly-half on his return from a ban.
'History'
George Ford is named on the bench, after starring in the No. 10 shirt in both their wins, opening the door to having the trio of playmakers on the field at the same time against the lowest-ranked outfit in the competition.
"Possibly at some stage, with the addition of George," Sinfield said.
"Marcus has been a world-class player for some time now.
"We understand the quality in the 10 positions and how do we get the best out of the three of them," he added.
This weekend's game marks the first meeting between the sides with Chile, known as Los Condores (The Condors), making their World Cup debut in France.
The South Americans are yet to win during the tournament, losing to Japan and Samoa.
"It's special because it's the most important game in Chilean rugby history," Chile lock Clemente Saavedra told reporters.
"That weighs on us but at the same time we're calm, we're at ease, we're relaxed.
"We want to leave the field completely empty, we want to leave everything on the field," the 25-year-old added.
