Tottenham boss Andre Villas-Boas boosted his attacking midfield options during the transfer window by bringing in the likes of Nacer Chadli, Christian Eriksen, Paulinho and Erik Lamela after selling Gareth Bale to Real Madrid.
Icelandic international Sigurdsson struggled to hold down a spot in Villas-Boas' starting XI last season and the 23-year-old knows it could be even harder to get in the side this term following the reshaping of the squad.
"We've brought in a lot of players and we have a very big squad," Sigurdsson told Fotbolti.net.
"Many good players have arrived and things are looking good. We have a strong group of lads so hopefully we can go far in every competition.
"I know that most of the teams in the top five of the Premier League buy a lot of players, and I knew there would be plenty of competition."
Sigurdsson also wished former team-mate Bale well after his record-breaking move to Real Madrid.
"It's probably a relief for him, I think," added Sigurdsson.
"The players aren't thinking too much about this but it's great for him to join one of the world's biggest clubs.
"I hope he does well there, but we've got some players instead for the money he brought in so hopefully we can reach that Champions League spot.
"He's a great player with a lot of pace and sharpness, and I just hope he starts doing well as soon as possible and fits right in."