Rafa Benitez lost Federico Fernandez and Kenedy on the eve of Cardiff City's visit to St James's Park.
Benitez had hoped to have defender Fernandez and winger Kenedy available for Saturday's game, which Newcastle United won 3-0 to move out of the Premier League's relegation zone.
However, the pair were laid low by a virus and were unavailable for selection.
"Fernandez and Kenedy both have a virus, so we were surprised the day before," said Benitez, United's manager.
Benitez was already without a number of players, including midfielders Jonjo Shelvey and Mohamed Diame.
"Diame was pushing, but he couldn't be ready," said Benitez. "He wanted to be available, but it was too difficult.
"Dummett and Jonjo, they are progressing and getting better, but still they didn't have time for this game."
Goalkeepers Rob Elliot and Karl Darlow are sidelined.
"We have Elliot with a problem that may need an operation on his back and Darlow that has the elbow (injury)," said Benitez.
Meanwhile, Ki Sung-yueng due back on Tyneside after being ruled out of South Korea's remaining Asian Cup games with a hamstring injury.
Yoshinori Muto is still at the tournament with Japan.
"We have too many problems with Ki (Sung-yueng) and Muto away, but the reaction of the game has been perfect," said Benitez.