The Iceland international made 12 starts in the Premier League last season and was linked with a move away from White Hart Lane following the arrival of Christian Eriksen, Nacer Chadli and Erik Lamela.
Sigurdsson got both goals as Andre Villas-Boas' side beat Norwich City last Saturday and is fully focussed on becoming a first-team regular.
The midfielder, signed from Hoffenheim in July 2012, has started two of Tottenham's four league fixtures this season and admits he was always going to fight for his future at the club.
"I wasn't close to leaving," he said. "I came here was to play for a big club. When I joined I knew there would be loads of players and competition.
"You can either be unhappy and leave or look at it as a challenge.
"Hopefully you'll improve and fight for your place as you know if you do the right thing every day things fall your way and I'm hoping that will happen."
