Liverpool have suffered numerous bouts of illness to their squad and Naby Keita is the latest to be on that list.
Speaking to reporters at Melwood on Tuesday, Reds boss Jurgen Klopp revealed the Guinean missed training due to sickness.
However, he was hopeful that he could return to action for Watford's visit of Anfield on Wednesday night as the Reds look to continue their charge in the Premier League.
“Naby was ill yesterday, unfortunately, but I’ve heard now, I got a message, that he is back for today,” Klopp said. “We have to see how he is.
“[Dejan is] getting closer; they are all getting closer, thank God – the injuries don’t get more serious in our rehab.
“But no, not for tomorrow – nobody else coming back.”
Keita would be a welcome inclusion to the side that drew at Old Trafford, with Liverpool looking short of creativity after two goalless draws on the trot.
Liverpool forward Roberto Firmino is also a doubt for the game after coming off in the first-half at Melwood with an ankle injury.
Klopp insisted that the Brazilian could feature against the Hornets on Wednesday night, whilst saying he should be fit for this weekend's trip to Goodison Park.
“[It] looks good,” said Klopp. “We were obviously lucky, it’s not as serious as we thought in the first moment; if Bobby leaves the pitch it’s a bad sign.
“Because we play tomorrow [againt Watford] it will be very close, but there’s a very big chance for the derby [on Sunday].
“Writing Bobby off is a big mistake, he recovers pretty quick.”