Rafa Benitez admitted that Salomon Rondon's short of fitness after the striker made his comeback.
Rondon came off the bench in this afternoon's goalless draw against Southampton at the St Mary's Stadium.
The 29-year-old, signed on loan from West Bromwich Albion, had been sidelined for a month with a thigh injury.
Rondon wasn't able to make an impact on the game, in which Newcastle didn't have a shot on target.
"I think it's clear in terms of having another striker with more competition," said Benitez. "But his match fitness needs to improve by playing games.
"He has been training with the team, but still he is a little bit far away from his best condition. He's another option."
Yoshinori Muto started the game, but the striker, signed from Mainz in the summer, didn't get a sight of goal.
"Muto, he was working hard also," said Benitez. "We needed from the strikers hard work and the pace. They were working really hard.
"After we needed substitutions to give us fresh legs. I'm happy with him, but still he needs to learn about English football. Still he's doing well."
The result saw United climb off the foot of the Premier League table.