Major League Soccer said Tuesday that a return in mid-May looked "extremely unlikely," acknowledging it might not be possible to play its full season.
"Major League Soccer continues to regularly evaluate the impact of the Covid-19 pandemic, including how it will affect our plans for the 2020 season," the league said in a statement.
"Although we hoped to return to play in mid-May, that is extremely unlikely based on the guidance of federal and local public health authorities.
"Our goal remains to play as many games as possible, and while we currently have enough dates to play the entire season, we recognize at this time that it may become difficult to do so."
MLS suspended play on 12 March as the coronavirus pandemic was shutting down sports worldwide.
On 19 March MLS said it would remain suspended for eight weeks, which would have brought them back on 10 May.
With competition on hold indefinitely, the league has also imposed a training moratorium for all clubs, which was scheduled to last through 24 April.
In an interview with ESPN, Garber said that the moratorium would be extended "at least a couple weeks".
Garber also said that MLS is exploring alternative formats for completing the season.
"From tournament formats and neutral locations, ultimately playing an abridged regular season, but doing everything to get as many games," Garber said.
He said that if play does resume he thinks it would likely be without fans in what he called "MLS Studio" games.
The commissioner said officials of the North American league are monitoring their counterparts in England and Germany as they implement testing and training protocols amid the pandemic.
"We continue to learn more every day from the medical experts, and we expect to have additional details in the coming weeks regarding when we can return to play," the league statement said.
"As we have throughout this process, we will update our fans with every decision, and we thank them for their support and understanding during this extremely challenging time."