Citing multiple league sources, Soccer by Ives first reported the pending deals on its website Sunday night.
Because of the league-wide moratorium on trades until after Saturday's MLS Cup, which was won by the Los Angeles Galaxy, Real Salt Lake officials declined comment on the report.
On Twitter, however, veteran RSL defender Chris Wingert said, "Can't believe some of these trade rumors seem to be coming true. Bummed about losing some good teammates."
Olave, Espindola and Johnson have helped form RSL's foundation for four years, but general manager Garth Lagerwey talked as early as August about the possible need to change the roster after the season.
"If we can't get it done with this team, we'll have to tweak some things," he told The Salt Lake Tribune.
Real Salt Lake finished with a franchise-record 57 points during the MLS season and earned the No. 2 seed in the Western Conference playoffs.
RSL failed to score a goal in a two-game aggregate playoff series, however, and was eliminated by Seattle, 1-0.
In his press conference after the second leg, coach Jason Kreis was asked about a possible shake-up of the roster.
"We'll see," he said.
Like his teammates, goalkeeper Nick Rimando expressed the hope RSL would return intact next season, although he admitted roster turnover is part of professional sports.
"I'm happy with these guys," he said. "I'm happy with this team. There is something special here and I think we're only going to grow. ... But it's a business and guys understand it. If there is change, we hope it's for the better."
If Lagerwey moves Olave, Espindola, Johnson and perhaps others, it could be a sign that he believes some young players are ready to handle increased roles for the club. That group includes midfielder Luis Gil, midfielder Sebastian Velasquez and forward Paulo Jr.
Olave turns 32 in April. He played a career-low 1,734 minutes in 21 games last season after being plagued by a hamstring injury over the final three months.
Espindola, 27, was second on the team behind Alvaro Saborio with nine goals. He also contributed seven assists in 30 games.
Johnson, who turns 26 on Jan. 21, is a member of the Canadian Olympic team. He finished with three goals and three assists in 26 games last season.