Tottenham manager Mauricio Pochettino says he is not worried about Christian Eriksen's contract situation and insists the club is "working hard" to tie him to a new long-term deal.

Eriksen's current deal expires in 2020 and there has been no breakthrough in talks between the club and the 26-year-old, which have been ongoing since last season.

"He knows [and] we know what we’re doing and of course we’re working hard," Pochettino said on Thursday.

"The club’s working to try to take the best decisions. Christian is going to take I think the decision that is best for him. We’re not worried. In football I’m never worried.

"But I prefer that he’s going to sign the new contract and spend a long time with Tottenham. It will be fantastic."

Eriksen has been among the substitutes for Spurs' past three league games after returning from a month on the sidelines with an abdominal problem in mid-October but he is expected to return to the XI for Saturday's London derby against Chelsea at Wembley.

He played 90 minutes in Denmark's Uefa Nations League win over Wales last Friday but he was replaced at half-time of Monday's 0-0 draw with the Republic of Ireland in a pre-arranged substitution.

"The players that were involved in the World Cup suffered some problems, so always we try to look after them and provide the best tools to perform," Pochettino added. "Christian, for different reasons, struggled a little bit in the last month. That’s why we look after him.

"I think he’s better now after the international break… I think to look after him before going to the national team was the best decision because he started in the last 10 days in two games, and to play against Crystal Palace for 90 minutes and then start in the last two games with the national team would be too much for him.

"But look, it’s our player and we need to look after our player, to take the best decisions for them."

Pochettino will definitely be without centre-half Davinson Sanchez, who is hopeful of returning from a hamstring problem before the end of 2018, Kieran Trippier, Danny Rose (both groin) and Mousa Dembele (ankle) but Jan Vertonghen is available again after missing nine matches with a hamstring injury.

The club's Argentina international trio Erik Lamela, Juan Foyth and Paulo Gazzaniga are doubts after competing in Wednesday's friendly win over Mexico and only returning to the club in the early hours on Thursday morning.

"There’s still one day more but it’s very good news that Jan's involved again with the group," Pochettino said. "In the last two weeks he was training very well and now we wait to wait until tomorrow and decide if we believe he can be involved for Saturday.

"They [the Argentines] arrived today so early – 6am in the morning they landed here in London. It’s true they don’t rest properly in the last few days, but still today for the game we’re going to try to take the best decisions to try to be close to winning the game. That is in the end our objective."

Maurizio Sarri's Chelsea will arrive at the national stadium unbeaten in 12 League games under the Italian but Pochettino suggested the former Napoli coach has an easier job without competing in the Champions League – like his predecessor Antonio Conte, who won the title in 2016-17 when the Blues were out of Europe.

"He's doing a fantastic job at Chelsea. He's a manager that I like a lot," Pochettino said.

"In the last ten years I think Chelsea was so impressive with Mourinho, Conte and they won titles. Of course they have an unbelievable squad. They are doing very well with Sarri this season, still unbeaten.

"It's true that first season with Conte they were [not involved in Europe] and the next season Chelsea struggled a little when they were in the Champions League.

"This season they are competing in the Europa League again and it's completely different for Manchester City, Manchester United, Liverpool or us because we're competing in the Champions League. It's a completely different competition.

"I am not surprised because Chelsea have an unbelievable squad and players. This summer they invested. They signed players, quality players and they added to the squad. But it's normal, they have one point more than us. It's not surprised me that they're doing very well."