McLaren has confirmed Lando Norris will replace Daniel Ricciardo again on day two of pre-season testing in Bahrain with the Australian reported to still be "unwell".
Lando Norris completed a full day of running on Thursday after standing in for Ricciardo and will again get behind the wheel on Friday morning.
A McLaren spokesperson said: "In a change to our planned programme, Lando Norris will continue driving the MCL36 this morning.
"Daniel Ricciardo began feeling unwell yesterday morning, and while showing signs of improvement, the team will continue to assess him before he resumes driving duties.
"Daniel has had several precautionary covid-19 tests during this time, which have been negative throughout."
On the opening day of running, Norris completed just 50 laps as the team battled to fix a brake problem and he ended the day sixth fastest.