Pratley has been in inspired form already this season, following on from his excellent season last time around in helping the Swans to the League One title.
Alongside Ferrie Bodde and Leon Britton he has formed one of the deadliest midfield trios outside of the Premiership and they play a major part in the Swans success since the return of Roberto Martinez to the club.
And that form has seen Pratley rewarded with a new deal to stay at the Liberty and was immediately described by Roberto as a player with Premiership potential
"Darren's had a great start to the season, his fitness levels are superb and he can be as good as he wants to be.
"It's another bit of good news for the football club to see a player of Darren's quality and talent committing himself to the club on a long-term basis.
"We've secured another player with Premiership potential – a player who wants to fulfil that potential with Swansea City.''
Pratley himself added "I'm delighted to get the new deal done early, with just one year left on my contract I couldn't sign quickly enough.
"I'm happy here; I'm enjoying my football and I'd like to think I've got a good relationship with the players, staff and the fans.
"The Gaffer has given me the role of playing the furthest forward out of the three,'' he added. "I've been told to try and push on and link up quicker with the central striker.
"I think it's worked well so far, although I am determined to grab a few more goals to go with the role.
"I've been fairly happy with my performances so far this season, but it's still early days and I am determined to improve as an individual and as a team player.''