Andre Villas-Boas' fourth-placed side have suffered successive top flight defeats to Fulham and Liverpool following a fine run of just one loss in 16 matches.
These defeats have seen Spurs drop to just four points ahead of Arsenal, who have a game in hand over their arch-rivals, and Sigurdsson is targeting a strong finish to the season, starting at the Liberty Stadium on Saturday.
He told the club's official website: "It's in our hands. We've tough games coming up and these are the games we all want to be involved in.
"We have to pick up as many points as we can and we've important matches against (Manchester) City, Chelsea, Everton all coming up.
"We need to pick up as many points as possible, starting at Swansea."
Sigurdsson scored seven goals in 18 games for the Swans last term after arriving on loan in January and he admits his old club will be a tough team to play against after pushing on this season, including winning the Capital One Cup.
"Swansea have been really good this season, won a trophy and they've done well in the Premier League," he said.
"They are a hard team to play against and as I said earlier this season, they've pushed on again, continued to perform well and I'm sure they'll be established in the Premier League for years to come."