Mike Petke's New York side had not lost in four games heading into last week's clash with Chicago but a 15-minute blitz after half-time from the Fire saw the visitors triumph 5-4 at Red Bull Arena.
The Red Bulls will fancy themselves away to Toronto, who have lost four of their past five games in MLS, although Ryan Nelsen's side did advance to the final of the Canadian Championship on Wednesday with a penalty shootout victory over the Vancouver Whitecaps.
Issey Nakajima-Farran scored the winning penalty for Toronto, as they prevailed 5-3 in the shootout, after the semi-final finished 3-3 on aggregate.
Toronto will face Montreal Impact in the two-legged final.
Ahead of the clash at BMO Field, Red Bulls coach Petke revealed he is considering changing both full-backs with regular left-back Roy Miller joining Costa Rica's FIFA World Cup squad, while right-sided defender Kosuke Kimura had a poor match in the loss to Chicago.
"We're not going to whole-heartedly throw all our eggs in one basket on Tuesday afternoon and say this is our starting left back. We have three solid days of training," Petke said on Tuesday.
"The players that we have in mind are going to have very good opportunities to show us they belong playing left back this Saturday."
While Petke denied Kimura was solely responsible for New York's loss to the Fire, he did reveal both Richard Eckersley and Chris Duvall are pushing for a starting spot at right-back.
"To me there are three players competing for that spot; Chris Duvall, Richard Eckersley, and Kosuke Kimura," the 38-year-old coach said.
The Red Bulls sit fifth in the MLS' Eastern Conference on 14 points after last week's defeat but would draw level with Sporting Kansas City and New England Revolution if they defeat Toronto, before the leading teams play later in the weekend.
Toronto are second from bottom in the East, although they have only played seven games - the least of all teams in the conference.
New York have not lost to Toronto in 10 meetings.
Sporting will face Chicago on Sunday after suffering a shock 2-1 loss to Philadelphia Union on Wednesday.
Philadelphia had not won in 10 matches but recovered after Sporting equalised with 10 minutes remaining, to score the winner a minute later.
Union will take on New England on Saturday.
Western Conference leaders - Seattle Sounders - will look to respond after a 5-0 thrashing at the hands of the Revolution last week.
Sounders will host San Jose Earthquakes, who are sixth in the West, while second-placed Real Salt Lake will take on Colorado Rapids.
In other fixtures, Houston Dynamo face Los Angeles Galaxy, FC Dallas will welcome Chivas USA to Texas and Portland Timbers line up against Columbus Crew.
