Major League Baseball informed teams on Tuesday that the start of the 2021 Triple-A season will be delayed by a month. As a result, MLB clubs will operate alternate training sites similar to those used during the pandemic-shortened 2020 season.

The Triple-A season initially was scheduled to begin April 6, but games will be pushed back to early May, around the same time the Double-A and Class A seasons are expected to start. Some Triple-A teams tentatively are set to begin their seasons on May 4, with the rest two days later.

"This is a prudent step to complete the Major League and Minor League seasons as safely as possible, and we look forward to having fans back in ballparks across the country very soon," Morgan Sword, MLB's executive VP of baseball operations, said in a statement.

With the COVID-19 pandemic causing the cancellation of the 2020 Minor League season, alternate sites were set up as part of MLB’s health and safety protocols, providing a nearby location for clubs to train and develop players during the shortened MLB campaign.

It's still undetermined how many players will be permitted at the alternate sites this year. Last season, clubs submitted 60-man player pools, and those who were included in a player pool but weren't on the active Major League roster were able to train at the alternate site. The difference this year is that there will be a concurrent Minor League spring training taking place in April, giving clubs more options for how to get their Minor Leaguers prepared for the season.

Reinstituting the alternate training sites will reduce risk by temporarily eliminating the commercial airline travel that would be necessary during the Triple-A season. The alternate sites also make it easier for MLB teams to oversee coronavirus testing and manage protocols.

Meanwhile, the delay of the Triple-A season increases the chance that players will be able to get vaccinated before the start of the season, as the COVID-19 vaccine continues to be rolled out throughout the country. On Tuesday, President Biden announced that there will be enough vaccine supply for every adult in the United States by the end of May.