The Tigers captain played only the opening 10 minutes before being hurt when he attempted to tackle Ulster second row Dan Tuohy, who received a yellow card as Flood was taken to an ambulance.
He was examined at the Leicester Royal Infirmary where Flood tweeted a photo showing a ‘thumbs-up’ gesture despite wearing a neck brace and he was released later on Saturday.
As the squad returned to training on Monday, director of rugby Richard Cockerill said: “You don’t want to see any player leaving the field on a stretcher, especially with the new season just a week away. Toby was taken to hospital, he had all the necessary checks, then he was released after a couple of hours and we’ll see how he recovers this week.”
Flood asked the club to pass on his thanks for all the messages which poured in from supporters during the weekend.
The game was held up for 10 minutes while the club’s medical stuff attended to the England international fly-half and then escorted him in the ambulance to hospital.