Bukayo Saka will be sidelined for "many weeks" after suffering a hamstring injury in Arsenal's 5-1 win at Crystal Palace, with manager Mikel Arteta describing his loss as a "huge" blow.
The England winger went down midway through the first half at Selhurst Park on Saturday and had to be replaced by Leandro Trossard.
"It is not looking good. He will be out for many weeks," Arteta said at a press conference, adding he could not be more specific.
The Spaniard said the loss of the 23-year-old, who has nine goals and 13 assists in all competitions this season, would force him into a rethink.
"Obviously he's a big player for us," he said. "You just have to see the impact that he has on the team, but it's going to be a really good exercise for all of us to think about ways to overcome another challenge – because we've already had a lot in the season."
Arteta said Saka was "gutted" and "really emotional" after discovering the extent of his injury.
He also revealed that fellow winger Raheem Sterling had injured his knee and would be out for a number of weeks.
"We have to look internally at what we have and be creative," said the Gunners boss, adding that he did not know if the club would sign a winger in the January transfer window.
Saka was filmed leaving Selhurst Park on crutches, souring what had been a comprehensive second win over the Palace in four days.
Arteta, whose third-placed team face Premier League strugglers Ipswich on Saturday, said he was confident that Saka would be back well before the end of the season.
"It's part of the development of a player," Arteta said. "At some stage, at this level, you are going to get injured – unfortunately badly."
"It could have been worse, it could have been something else that can take you out for a year," he added. "It's how you react to that, how you overcome that situation."
Arteta said he was "putting some ideas together" about how to cope in the winger's absence.
Asked if the congested fixture schedule had played a part in Saka's injury, Arteta said the issue was more to do with consistently high workloads over many seasons.
"For example, Bukayo and Declan (Rice), they played over 130 games in two seasons," he said. "So what's going to happen in the second one, the third one or the fourth one, if that continues the same way? It's unsustainable." (AFP)