Fulham have not revealed the identity of the two players but they will self-isolate in line with EFL and government guidance.
Blackburn confirmed in a statement that their captain Elliott Bennett was the third of those whose results returned positive after 1,030 players and club staff were tested on Monday, Tuesday and Wednesday this week.
The club said that Bennett, 31, initially submitted a negative test on Friday May 22 , but tested positive when he underwent a second test on Monday.
He is asymptomatic and is feeling no ill-effects but will self-isolate at home for the next week, according to the Championship club.
“I feel fit and healthy,” Bennett told the club’s website. “Hopefully this sends out a positive message to the community that perhaps many people have or have had the virus without showing any effects.
“I obviously would never have known if we hadn’t returned to training and taken the tests, because I don’t feel unwell and have got no symptoms whatsoever.
“There seems to have been a lot of hysteria about footballers returning to training, but it’s not a big deal at all. It’s the people who are seriously ill in hospital that we need to worry about, not footballers who are fit and healthy, and who aren’t showing any signs of being unwell.”
In the EFL’s last round of tests, two persons tested positive from 1,014 tests. It was revealed the two people were at Hull City.