diallo

Captain Frank Dancevic says there’s plenty of unknowns as ninth-ranked Canada prepares to host No. 18 Brazil in this weekend’s Davis Cup Qualifiers first round.

Canada will be led by 24-year-old Gabriel Diallo of Montreal, who is ranked 39th in the world, and Liam Draxl of Newmarket, Ont., who is 146th.

Brazil does not have a have a top-200 singles player in its lineup.

“It’s a challenge because you’re playing an opponent that you don’t the know the feeling of his (serve)...