Brazilian winger Jackson is suspended for the game at Rio Tinto Stadium while Canadian midfielder Jonathan Osorio left practice early Friday, seemingly favouring his right hamstring.
Manager Ryan Nelsen said Osorio has been nursing a hamstring strain.
During the portion of Friday's training session open to the media, Mark Bloom was playing in place of Jackson on the right flank, with England's Bradley Orr taking over at fullback behind him.
"We don't have a great deal of options at the moment there but we've got a bit of versatility with Bloomie being able to play both positions and now Brad Orr's getting fit," said Nelsen.
Jeremy Hall slotted into central midfield alongside U.S. international Michael Bradley when Osorio exited.
Attacking midfielder Dwayne De Rosario remains another option — more likely playing wide left or coming on as an impact substitute — with Canadian international midfielder Issey Nakajima-Farran a newly signed, speedy asset on the flank.
But Nelsen has shown faith in the 26-year-old Bloom.
Toronto (2-0-0) is off to its best ever start with wins in Seattle and at home against D.C. United. But there are concerns over its depth outside the starting lineup with Nelsen looking to reinforce the 12 through 20 members of the roster.
Real Salt Lake (1-0-2) has played two of its first three games on the road, with a home-and-away series with the Los Angeles Galaxy already in the books.
While RSL has some injury concerns of its own, the team is a veteran outfit that is used to playing 4,500 feet above sea level.
England striker Jerman Defoe says he is no stranger to playing at altitude after his experience at the 2010 World Cup in South Africa. He saw the bigger challenge in the experience of Real Salt Lake.
"It's going to a massive test for us to go there and try to win the game," he said. "But at the minute, we're confident. Everyone's playing well, everyone's fit. We just look forward to it."
De Rosario, who helped D.C. United beat Real Salt Lake in the U.S. Open Cup final in Sandy, Utah, last season, agreed.
"It's a team that's been together for quite some time. A team that has a very distinguished system and they stay true to that. And they're very good at home."
Now in its 10th MLS season, Real Salt Lake is 74-31-39 at home in regular-season league play. In its eighth MLS campaign, Toronto's road record is 15-72-25.
But most of Toronto's past record for futility can be thrown out, with such marquee reinforcements as Defoe, Bradley, De Rosario and Brazilian striker Gilberto and goalkeeper Julio Cesar.
Real Salt Lake has injury concerns up front with Robbie Findley yet to play this season and former TFC player Joao Plata sidelined due to a hamstring strain. Plata, a five-foot-two 135-pound ball of Ecuadorian energy, has been red-hot to start the season with two goals and two assists in three games.
Alvaro Saborio and Olmes Garcia are expected to start at forward although Devon Sandoval could return from a foot injury.
Defender Aaron Maund, another Toronto FC alumnus, and midfielder Sebastian Velasquez, are also sidelined. Jordan Allen and Kwame Watson-Siriboe are listed as questionable.
RSL can still field a veteran lineup, however, led by the likes of midfielder Kyle Beckerman and goalkeeper Nick Rimando, both U.S. internationals.
After playing a poor pitch at BMO Field in its home opener, Toronto won't see much of an improvement in the Rio Tinto Stadium surface.
"It's in really bad shape," said Beckerman.
NOTES — Toronto is 1-5-0 lifetime in Utah ... RSL edged Toronto 3-2 on a stoppage-time goal the last time the clubs met in Utah, on April 28, 2012. Only Doneil Henry, Ashtone Morgan and Quillan Roberts remain with the club from Toronto's 18-man roster that day ... Nelsen says the cub has talked to Jackson about resisting the temptation to retaliate when provoked on the field.