Somerset's Jack Brooks became English county cricket's first Covid-19 substitute when he replaced Lewis Gregory on the third day of a Championship match against Middlesex at Taunton on Saturday.
Gregory's girlfriend, a member of his household bubble, felt unwell and although she has returned a negative lateral flow test, the England white-ball all-rounder will now isolate until a second negative result, from a PCR test, is returned.
Under the England and Wales Cricket Board's Covid replacement regulations, substitutions can be made if a player tests positive for the coronavirus, shows symptoms of the disease or requires removal from the game for any other reason related to public health guidance.
The rules state a like-for-like replacement should be made where possible and, although Brooks is best known as a seamer, he was cleared to take part by match referee Wayne Noon.
Once replaced, a player cannot return to the match in question, even if he submits a negative Covid test.
Gregory was one of several English players involved in the Pakistan Super League when it was suspended in March after a coronavirus outbreak within the tournament bubble.
"Somerset County Cricket Club can confirm that Jack Brooks has been made available as a Covid-19 substitute for the remainder of the current LV= Insurance County Championship match against Middlesex at the Cooper Associates County Ground," said a club statement.
At close of play, Somerset required a further 103 runs to beat Middlesex with six wickets in hand.
- Roach strikes -
Elsewhere, West Indies fast bowler Kemar Roach took a career-best 8-40 as Surrey overwhelmed Hampshire by an innings and 289 runs inside three days at the Oval.
This was Surrey's first County Championship win of the season, after two losses and a draw.
By contrast, it was a first defeat for Hampshire after two wins from three matches.
Hampshire were dismissed for 179 in their second innings, with the visitors having been behind in the match after they were skittled out for just 92 in their first innings.
Roach struck during an initial burst of 3-21 in 11 overs.
He continued to take wickets before ending the match when he had Lewis McManus caught behind for a game 51.
Surrey previously declared their mammoth first innings on 560-7.
That huge total featured an unbeaten 215 from Hashim Amla, the South Africa great retiring hurt on his overnight score because of a stiff neck.
Meanwhile, England stalwart Stuart Broad took 4-37 as Nottinghamshire thrashed Midlands rivals Derbyshire by 310 runs at Derby to secure their first red-ball win since 2018.
Durham beat Warwickshire by a crushing innings and 127 runs to record their first Championship win of the season, with paceman Brydon Carse taking 5-49.
This season, partly in response to Covid-19, the 18 counties have been split into three groups of six rather than two divisions.
The top two teams in each group will qualify for Division One, with the winners of that league the 2021 county champions.