Mauricio Pochettino expects Tottenham striker Clinton Njie to be out for two to three months with a knee injury.
Njie has undergone surgery after sustaining the injury in Spurs' Europa League victory over Monaco two weeks ago.
The Cameroon forward initially struggled with a hamstring problem when he arrived from Lyon in the summer and the 22-year-old is now expected to be on the sidelines until March.
"I don't know but we will expect maybe two months or two and a half," Pochettino said.
"You never know because every day it's about how the knee responds but maybe two months or a little bit more."
The setback leaves Tottenham even shorter of forward options with Harry Kane currently the club's only out-and-out first-team striker.
Pochettino insists Njie, Son Heung-min and Nacer Chadli can play up front but all three are more comfortable in an attacking midfield role and Spurs are now likely to step up their search for another striker in January.
Tottenham moved into the top four for the first time this season after beating Southampton last weekend and a win at home to Norwich on Saturday could see them climb to third.
Pochettino believes his young side do not always get the credit their performances deserve and the Argentinian refused to rule out a potential title challenge.
"People don't realise the effort we make and how hard our players work because we are the youngest squad in the Premier League," Pochettino said.
"Sometimes they deserve more praise for the position they have. Maybe the team deserve more praise than we have so far."
Pochettino added: "Can we win the title? In football, all is possible.
"The last 10 games are very important and it's how you arrive there to attack different objectives or achieve important things. It's important how we arrive in the last 10 games."
Danny Rose is available again after missing the win over Southampton through illness while Ryan Mason is also back in contention.
The midfielder returned to training this week, having recovered from an ankle injury, but Alex Pritchard (ankle) is still out.