Questions abound about Canadian 4x100m relay team selections at athletics worlds

With injuries mounting at the World Athletics Championships and the men's 4x100-metre relay heats set for Friday, questions abound about what the competing country's lineups are going to look like.

Canada's sprinting superstar Andre De Grasse withdrew from the 200m event, having contracted COVID-19 for a second time less than a month ago. De Grasse has said he'll be good to race the relay.

Italy's Olympic champion in the 100m Marcell Jacobs withdrew from the final of the event due to injury. Italy won Olympic gold in Tokyo in the relay.

Yohan Blake, one of Jamaica's top runners, didn't run the 200m semifinal on Tuesday night due to what's been reported as a foot injury. Blake, however, was practicing handing off the baton at a track near Hayward Field on Wednesday afternoon.

WATCH | Canada's chemistry a factor ahead of 4x100 relay:

And American Fred Kerley, who won the 100m world title earlier at worlds, failed to advance in the 200m semi on Tuesday evening after pulling up during his heat. Kerley was visibly in pain after the race. He has, however, told reporters it was just a cramp and that he should be able to race in the relay for the heavily-favoured Americans if selected.

Athletics Canada head coach Glenroy Gilbert, who was part of that unstoppable Canadians relay team in the mid-90s winning two world titles and Olympic gold, says the relay team competing in Eugene, Ore. will be determined Thursday night.

And Gilbert says whoever is in the lineup in the relay heats for Canada will go the rest of the way.

"Who lines up on Friday, barring any injuries, will be the same people in the final. I don't like to move pieces around, especially when you only have two rounds," he said.

At this point of the world championships