Prolific Sydney Swans ball winner Josh Kennedy says the team regards Saturday's opponent, the rejuvenated Western Bulldogs, as a quality side.

And he says the key for the Swans is to get off to a quick start, something they have failed to do this season against Fremantle and Essendon.

The dual All Australian said he's been impressed by the Dogs' surprise start to the year after a tumultuous off-season had many predicting a near bottom of the table finish for the club in 2015.

The Bulldogs sit sixth on the premiership ladder, two spots below the Swans, but share a 3-1 record, and are coming off a 57-point win over the previously unbeaten Adelaide.

Kennedy paid tribute to the Bulldogs and said there was no way the Swans would treat them as anything other than a top quality side.

"We see it as a game that we want to win, that we should win – we go into every week thinking we want to win," he said.

"The Bulldogs are a really good contested footy team, so we're going to have to bring our best in that area to compete with them.

"They're a really damaging team, especially across half-back, with (Bob) Murphy, and (Matthew) Boyd going back there as well, really just straightening them up.

"We've got to try and focus on the start this week and not give them the head start we gave Fremantle last week."

Kennedy could find himself matched up against young Dogs' tyro Marcus Bontempelli this week, the runner-up in last season's NAB AFL Rising Star award.

The rangy left-footer has been a vital part of the Bulldogs' strong start to the season, combining brilliant skills by both hand and foot with a strong appetite for winning contested footy.

In his three matches in 2015, Bontempelli averages 22 disposals per game, but has also laid 27 tackles and been a nightmare for opposition midfields because of his height and strength at clearances.

"He's taken his game to another level in the midfield, a really strong and damaging player there. We'll back ourselves, though, and whoever lines up on him we'll have full faith that they can impact the contest," Kennedy said.

"We've got a lot of confidence in our midfield as well, so it'll be a good contest in there all round."