Warnock, 71, did not take charge of Boro’s 2-0 Carabao Cup second-round defeat at home to Barnsley on Tuesday night and will now spend time self-isolating.
“The club can confirm that our manager Neil Warnock has returned a positive test for Covid-19 and will be spending a period in isolation in accordance with guidelines,” a Middlesbrough statement read.
“Neil is in good spirits and we look forward to welcoming him back after his period in isolation.”
The club can confirm that our manager Neil Warnock has returned a positive test for COVID-19 and will be spending a period in isolation in accordance with guidelineshttps://t.co/Syk0V1z1W6
— Middlesbrough FC (@Boro) September 17, 2020
Warnock watched the Barnsley loss from an executive box having felt unwell upon arriving at the Riverside Stadium.
His assistant, Kevin Blackwell, took charge of the game and a similar set-up will now be required for Saturday’s Championship clash at home to recently-relegated Bournemouth.
The fixture has been selected as a trial game for the gradual return of supporters following the coronavirus pandemic, with 1,000 fans set to be admitted on Saturday.
Warnock was appointed as Middlesbrough boss in June on a short-term basis but, after keeping the club in the second-tier, he signed a deal to remain in charge for the 2020-21 season.