Middlesbrough boss Neil Warnock would prefer his players to get the Covid-19 vaccine, to help protect them against the virus within the community.
Warnock, 72, admitted the "majority" of his squad are yet to be vaccinated and that there have been recent positive cases within the club.
The lowering of government restrictions has brought players into more contact with the public in their daily lives.
"We've just got to be so careful," Warnock said at his press conference.
"We've had a few sniffs of the virus, which we've got to overcome and we're still getting tested every day.