England fly-half Toby Flood was taken to hospital on Saturday after a heavy collision during Leicester's pre-season match against Ulster.
Flood, 28, was injured early in the match at Welford Road, and calmed fears about his condition by Tweeting a picture of himself in a neck brace, adding the caption: "How's everyone else's day going?"
Leicester's official website reported Flood collided with Ulster's Dan Tuohy, who was yellow-carded by referee Tim Wigglesworth.
Burke is the Leicester backs coach.
The picture posted by Flood shows him with what appears to be a small amount of blood below an eyebrow, and with a thumbs-up at the side of the shot, although it is not clear whether the thumb is Flood's.
Leicester won the match 30-10, with play resuming after a 10-minute break once Flood was carried off on a stretcher.
The fixture was arranged to help Leicester with their preparation for the new Aviva Premiership campaign, which for the Tigers begins next Sunday, September 8, with a home game against Worcester.
Ulster stated on their Twitter feed: "Best wishes to Leicester's Toby Flood who was injured in today's game. Hoping he makes a speedy recovery."
Burke said after the match that it was out of "precaution" that Flood went to hospital.
"He was taken straight to hospital but has come around," Burke said.
"I believe he took a blow to the head and they have a protocol which took place, then they took him to hospital as a precaution. They are doing all the necessary stuff at the moment. We will keep you updated."
Burke added, according to leicestermercury.co.uk: "I am not aware of any blood (from the incident). He took a direct blow to the head but we will have to have a look at the incident again.
"It's too early to put any time frame on the injury. We will get the advice from the medics and take it from there."
Flood has won 57 England caps, and ahead of his sixth season at Leicester he has been appointed to captain the team, it was recently announced.