The striker was forced off in the first half of Leicester's game against fellow promotion contenders Burnley on Saturday and is now awaiting the results of a scan on a groin injury.
"We don't know the extent of the injury," Pearson revealed to the club website.
"It's a disappointment for us because he's been playing so well, but I suppose looking at how the game on Saturday finished with Chris Wood coming on to have a positive impact, it shows that we do have options.
"We know that it will be a disappointment if we do have to miss him for any length of time, but we know that we've got very capable players to step into the side."
Wood replaced Vardy and set up Leicester's first goal before sealing the win with a dipping 25-yard volley at Turf Moor.
Three points saw Leicester move 15 points clear in the automatic promotion places as they close in on a return to the Premier League after 10 years out of the top flight.