Manchester City striker Gabriel Jesus and defender Kyle Walker have tested positive for Covid-19.
The players, along with two members of staff, will isolate in accordance with Premier League and government protocol.
Jesus' obvious replacement Sergio Aguero is being eased back after a knee issue and played 16 minutes on Tuesday.
Brazil forward Jesus, 23, has scored four times this season but was missing through injury for a month while 30-year-old Walker has been a virtual ever-present for Pep Guardiola's side.
England right-back Walker apologised in May for breaking coronavirus lockdown guidelines twice.
Manchester City are eight points behind Premier League leaders Liverpool with a game in hand.