We know what former NBA coach and prolific quipster Frank Layden would say about Tacko Fall, the Boston Celtics newest signee: "You can't teach height."

Layden dropped the enduring phrase back in 1982, in reference to Mark Eaton. But Eaton, who went on to have a solid, 12-year career, was a full three inches shorter than Fall, who stands 7-feet, 7-inches. And although Fall has not exactly been tearing up the Las Vegas Summer League, Boston made him a Celtic Thursday, signing him to an Exhibit 10 contract for the 2019-20 season, according to The Boston Globe. If he sticks, he will be the NBA's tallest player.

"Excited to be part of the Celtics' organization. It's the beginning of seeing my dream come true," tweeted Fall. "There is still lots of work to be done to secure a spot on the active roster by the time the season starts. Gonna stay humble but I'm hungry and determined!"

CELTICS' ROOKIE'S INCREDIBLE HEIGHT SHOWN IN THIS AMAZING PICTURE

The two tallest players ever to suit up in the NBA are generally considered to be Gheorghe Muresan and Manute Bol, who both also measured 7-feet, 7-inches.

In five games for the Celtics' Summer League team, Fall averaged 7.2 points, 4.0 rebounds, and 1.4 blocked shots. But he also shot an amazing 77.3 percent from the field and had two double-double games in his five contests.

Fall played his college ball at Central Florida, where he averaged 10.1 points, 7.7 rebounds, and 2.4 blocks.

CLICK HERE TO GET THE FOX NEWS APP

There's no guarantee Fall will make the team out of training camp, but if he fails, it won't be for lack of height - or determination. Fall was born in Senegal and grew up playing soccer. He came to the U.S. at age 16, and first played basketball here when he trained with former NBA legend Hakeem Olajuwon. In one memorable moment from his collegiate career, Fall tipped off against fellow Senegalese big man and UC-Irvine center Mamadou N'Diaye, who is just an inch shorter. Their combined heights set a record.