Newcastle United forward Anthony Gordon has not trained this week and will miss Saturday's Premier League match at Nottingham Forest, manager Eddie Howe said on Friday.
Gordon, who has made 22 league appearances for Newcastle this season and scored seven goals, left the stadium on crutches after twisting his ankle during Newcastle's 4-4 draw with Luton Town on Feb 3.
"Anthony hasn't trained this week but we don't think the injury is serious. We hope he is back sooner than later," Howe told reporters.
Newcastle are already without forward Alexander Isak, Brazilian midfielder Joelinton, goalkeeper Nick Pope and others through injury.
"Alex won't make this game, we hope he won't be too far away, we don't have a fixed date yet. He is making good progress," Howe added.
Ninth-placed Newcastle have 33 points from 23 matches, while Forest, 16th, have 21 points and are two points above the relegation zone.
Isak gave Newcastle the lead against Forest in the reverse fixture in December, but Howe's team lost 3-1 after their former striker Chris Wood scored a hat-trick.
"Any defeat at home hurts badly. That day, at 1-0 up, the game was there for us. We just needed to keep on attacking and we didn't do that," Howe said.
Howe also criticised the proposed introduction of blue cards by soccer's rule-making body IFAB on a trial basis, which would allow a referee to suspend a player for 10 minutes over dissent or cynical fouls.
"I'm not a big fan to be honest, that's what yellow cards are for. The system works but just needs to be refined. Blue cards would just add confusion so I'm against it," Howe said.
FIFA clarified on Thursday that reports that blue cards would be introduced at football's elite levels were "incorrect and premature".