Toronto FC's Nick DeLeon and Tsubasa Endoh and Vancouver's Tosaint Ricketts and Andy Rose are among the 127 MLS players eligible for free agency.
All four are out of contract.
Toronto and Vancouver also have players who are out of contract but have an option year remaining on their contract.
For the Whitecaps, that category is restricted to defender/midfielder Florian Jungwirth, acquired in early August in a trade with San Jose. The 32-year-old German made 14 appearances for Vancouver.
Toronto players going into their option year are centre back Omar Gonzalez, forward Patrick Mullins, midfielder Jonathan Osorio and centre back Eriq Zavaleta.
Gonzalez, who turned 33 last month, is a big-ticket item with a salary of US$1,055,960 this season for a Toronto defence that gave up a franchise-worst 66 goals.
The 31-year-old DeLeon, a midfielder who has spent the last three seasons with TFC, seems destined to leave Toronto. He played just 628 minutes in league play this year, the lowest in his 10-year MLS career.
His wife and two kids are back in Arizona where they have a better support system with family nearby.
In August, he said he knows what he plans to do after this season but declined to specify other than to say: ``I'm not retiring.''
DeLeon was the lone TFC player to say -- in March -- he had no intention of getting the COVID-19 vaccine.
It marks the first time the free agency list has been released publicly by the Major League Soccer Players Association.
The association, citing changes in the latest collective bargaining agreement, says the number of 127 free-agency eligible players is a 149 per cent increase from the same period two years earlier (2019-2020).
The association says 26 per cent of the current MLS player pool meets the eligibility threshold for free agency, compared to just 11 per cent in the final year of the last CBA.
The new deal reduced eligibility requirements to 24 years old with five years of service as opposed to 28 and eight years of service.
