LONDON -- Tottenham centre-back Toby Alderweireld is likely to be sidelined until after Christmas with a hamstring injury, according to manager Mauricio Pochettino.
Alderweireld pulled up in the 3-1 win over Real Madrid on Nov. 1 and he said afterwards he would be out for "a few weeks."
But Pochettino, speaking ahead of Saturday's North London derby at Arsenal, said the injury was worse than first feared.
"Toby is out. We need to assess him but we expect longer than previously we thought when the problem happened," Pochettino told a news conference on Thursday.
"Maybe after Christmas -- that's the expectation. It will be longer [than we thought]. The injury is in his hamstring. It's only him and Victor Wanyama [who are injured] then, who we assess every day. We need to wait."
Alderweireld missed the 1-0 win over Crystal Palace a fortnight ago and Spurs have nine matches before Christmas: the Champions League group games against Borussia Dortmund and APOEL Nicosia, and meetings with West Brom, Leicester, Watford, Stoke, Brighton, Manchester City and Burnley in the Premier League.
"He feels normal, feels disappointed, a little sad," Pochettino said, adding that the injury is "completely different" to the nerve damage that sidelined the Belgium international for six weeks last season.
"In the same way, he's focused on recovering as soon as possible, working hard in the first stage of rehab," he said. "We're happy. Always, in first stage on injury, you need caution. It's a process of time. We need to wait."
There was better news on Spurs' other fitness doubts after Harry Kane (knee), Hugo Lloris (groin), Harry Winks (ankle) and Dele Alli (hamstring) all returned to full training on Thursday.
"For first time today, all the players arrived from the international break and we need to assess all of them tomorrow -- we have one more training session. We're optimistic but we need to wait to analyse every single case," the Spurs manager said.
"We hope tomorrow we can count on them for the game but we still need to decide between the medical, the sports science staff and us. I'm happy because if they cannot play Saturday, be sure they're close to playing Tuesday [against Dortmund] or next weekend [against West Brom]. It's not a big issue like Toby Alderweireld."
Pochettino also said he was still waiting for Erik Lamela to say when he was "ready" to return from hip problems after over a year on the sidelines.
Spurs go into Saturday's match as favourites, having finished above Arsene Wenger's Arsenal in the league for the first time 22 years last season, but Pochettino says the Frenchman is one of the greatest managers in football history and should not be underestimated.
"For me, in football history he's one of the great managers, at the same level as [Sir Alex] Ferguson, and in my opinion he deserves a lot of credit," Pochettino said.
"For me he's great. [It doesn't matter] what happens today, yesterday or one year ago or in the future, he'll always be a special manager. To stay 20 years in a club and stay always at the top, it's not easy and that is why for me it's a reason to admire him.
"Of course Ferguson and him, they're managers that for me I always look at. To stay in a club for five years, it is because you are a good manager; 10 years it is because you must be very good. For more than 20 years, it is because you are special.
"I don't what underdogs means. Arsenal is a great team. There is not a favourite in this type of game. In the last 22, 23 years only we finish above Arsenal one time. That does not mean today we are above Arsenal.
"We must respect them. They were great under Arsene Wenger's era. We need to build our project, our era too. Of course, we need to fight and try to win. Arsenal, not only in the past, but today they have a great team, a great manager. We need to show massive respect to them."