"I don't know if it will happen ever again, that's how slim the chances are," said Pratley.
"Nothing is promised in this game so when you've got the chance like we have now, we've got to try and take it."
Six-goal top scorer Pratley has played a key role in the heart of the Swansea midfield this season.
The former Fulham midfielder's displays have attracted the attention of play-off rivals Nottingham Forest.
But he has yet to have a run in top-flight football - making just one substitute appearance - and is eager to achieve that goal.
"You don't get many chances," Pratley told the BBC's Sport Wales programme.
"Many people in their careers don't win league or get titles but we were lucky enough to win League One and now it's a chance for us to go on and get into the Premier League.
"In our careers, which are short in football, this opportunity doesn't come around every year."
But if Swansea are to reach the Premier League, they need to turn their form around starting with the visit of Barnsley to the Liberty Stadium on Saturday.
Paulo Sousa's side have been in the top six since December but their recent slump in form has seen the gap between them and Blackpool, who sit just outside the play-offs, cut from eight points to two with three games to go.
"We can't put too much pressure on ourselves otherwise we won't perform how we want to," said Pratley.
"The only way you can put it right is by going out on Saturday and getting the three points.
"If you get the three points on Saturday, it's two more games to go and hopefully we can get in there.
"There's a big prize at the end of it and it's in our hands.
"If we win the next six games, we are in the Premier League."
See more of the Darren Pratley interview as part of a special Sport Wales feature on the climax to the promotion race. Sport Wales is on BBC TWO Wales on Friday at 2100 BST.
Source: BBC Sport
Source: BBC Sport