On Thursday, the court issued a ruling quashing an arbitrator's decision in June that Williams's contract with the Hamilton Tiger-Cats was binding even though the club violated the CFL's collective bargaining agreement with the CFLPA.
"It is the position of the CFLPA that Chris Williams is now a free agent and able to sign a contract in the NFL or another CFL club," the union said in a statement.
Dan Vertlieb, Williams' agent, didn't immediately respond to an email request for comment from The Canadian Press.
Williams, 25, the CFL's top special-teams player last season, went to arbitration asking to be released from the final year of his contract with Hamilton to reportedly pursue NFL offers.
In June, arbitrator E.E. Palmer found the Ticats violated the CBA by negotiating with an unregistered agent but said the penalty was a fine and not the termination of the contract.
However, the Ticats weren't fined because the CFLPA did not request one be imposed.
Palmer also found Hamilton had picked up the option on Williams's contract last October in accordance to the CBA but didn't use the exact language surrounding the renewal as laid out in the agreement.
But he also ruled that wasn't enough to null the agreement.
Both the Ticats and CFL said they'll appeal Thursday's ruling.
"We plan to appeal today's decision in the Chris Williams case to the Court of Appeal," the CFL said in a statement. "Until that appeal is exhausted, our position is that Williams remains under contract to the Tiger-Cats."
Added the Ticats: "Our position remains that Williams is under a legal and binding contract with the Tiger-Cats. We have faith that the outcome of our appeal will validate that position. We plan no further comment at this time as the matter remains before the courts."
Williams's bitter contract dispute with the Ticats has spilled over into the start of the regular season as the star receiver has yet to report to the CFL club.
The CFLPA contends the arbitrator's decision was "quashed and set aside on the grounds that the letter purporting to exercise Chris Williams's option was not clear and was not capable of being construed as a clear communication of an intention to exercise the option."
Williams signed a deal with Hamilton in 2011 that was negotiated by an agent not registered with the CFL Players’ Association. Williams reportedly contends he wasn't made fully aware of the conditions pertaining to his rookie contract and that Hamilton didn't offer him the one-year plus an option deal but rather just the two-year plus an option.
"There is no clear and unequivocal language along the lines, 'The Hamilton Tiger-Cats exercises its option to require you to play for another year for this club,'" Justice Gladys Pardu said in her ruling Thursday. "The language used in the less is not capable of being construed as a clear communication of an intention to exercise the option and the arbitrator's conclusion that it was clear was unreasonable.
"The subjective intentions of the Tiger-Cats are no substitute for clarity in expressing the intention to exercise the option. On this ground, the arbitrator's decision must be quashed."
The court also ruled the Ticats must pay court costs of $8,500.
Williams was reportedly scheduled to earn base salary of $48,000 this season. That pales in comparison to both the NFL’s minimum salary, which is US$405,000 this year, or the roughly US$90,000 players south of the border can earn annually on the practice roster.
Williams had a Ticats-record 17 TDs last season, including a CFL record six on kick returns.
The five-foot-eight, 175-pound Williams was named the CFL's top rookie in 2011 after registering 70 receptions for 1,064 yards and six TDs. He also had 12 kickoff returns for 252 yards and a touchdown while returning 12 punts for 81 yards.
Williams was even better last season, with 83 catches for 1,298 yards and 11 TDs. He also led the CFL in punt returns with 78 for 1,117 yards and five touchdowns while adding five missed field goal returns for 256 yards and a TD.
Williams played his college football at New Mexico State and joined the NFL’s Miami Dolphins as an undrafted free agent in 2009 but was released with an injury settlement prior to the start of the season. He signed with the Cleveland Browns later in the year and spent time on the practice roster before being let go.