The in-form midfielder spent the second half of last season on loan at the Liberty Stadium from Hoffenheim and caught the eye with seven goals in 18 games for the Swans.
Swansea finished 11th on 47 points last term but currently sit ninth with 40 points already in the bag.
They also celebrated their first major trophy success by winning the Capital One Cup in February, booking a place in Europe in the process.
“Swansea have been really good this season, won a trophy and they’ve done well in the Premier League,” said Gylfi.
“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.”
Although looking forward to returning to the Liberty, Gylfi was quick to stress that it was all about us as we look to get back to winning ways in the Premier League.
Defeat last time out against Fulham made it two on the trot in the Premier League after a fantastic run of one loss in 16.
Back after the international break – where Gylfi scored both goals in Iceland’s win against Slovenia – the squad is determined to kick-start another run for the final eight games.
“It’s in our hands,” said Gylfi. “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 City, Chelsea, Everton all coming up. We need to pick up as many points as possible, starting at Swansea.”