Under Armour has secured its first major professional sports uniform deal. The shoe and apparel company will take over for Majestic Athletic as the official on-field uniform provider for Major League Baseball beginning with the 2020 season.

Team sources confirmed the deal, which also gives Fanatics -- the nation's largest seller of online sports gear, which already runs the online MLB Shop -- rights to produce and customize jerseys and sell them at retail.

It is unclear how the two new partners will divvy up the rest of what is made for the players and eventually sold to the public. New Era will continue to provide headwear for the league.

Under Armour and Fanatics get the next MLB uniform deal, but hats will still be made by New Era. Brace Hemmelgarn/Minnesota Twins/Getty Images

The current on-field jersey deal is owned by Majestic, which has produced MLB jerseys since 2005. The only rights Fanatics had to date was to make fan apparel, mostly designing apparel with team logos on it.

Spokespeople for Fanatics and Major League Baseball said they would have no comment on the news, which was first reported by Sports Business Daily. An Under Armour spokesperson was unavailable for comment.

It is not known whether Fanatics will be the sole wholesaler of the jerseys, meaning that they will also make uniforms not sold through their channels, including brick and mortar retail stores.

Under Armour was a bidder to pick up the official NBA uniform rights deal, which begins next year and was ultimately won by Nike. Nike had rights to have its product on the under layer under the MLB jersey, but they will be out with the new deal, sources said.

Under Armour also has a deal with the NFL, which provides that its workout gear will be worn by players at the NFL Combine each year.

Serving the licensed youth business will also be up for review, Sports Business Daily reported. Outerstuff, which has the NFL as an equity partner, controls of most of that marketplace.