Unlike the NBA, the WNBA prohibits players joining its league directly out of high school. Nor does it accept players leaving college early.

Teresa Weatherspoon, for one, agrees with this rule, and hopes it doesn’t get challenged in court.

At the same time, Weatherspoon realizes that the WNBA salary structure is not likely to lure many under-21 players, anyway.

But with the rise in popularity in women’s basketball, from college to the WNBA, the Liberty star guard said the league needs to increase the players’ pay-scale.

“We just have to go to the table to fight as hard as we can,” Weatherspoon said yesterday at Basketball City in Chelsea, where she was part of Net Gain 2001, a Wall Street-sponsored charity to raise money for public high-school sports facilities.

Including bonuses, the WNBA’s average salary last season was $55,000 over the three-month season. The minimum salary for a veteran was $32,500, while salaries began at $26,500 for a rookie.

Under the league’s collective-bargaining agreement, the salaries increase each year during the four-year agreement, which is entering its third year. However, the league does not permit free agency, which would allow players to shop themselves to the highest bidder.

Since its inception in 1997, the WNBA has not broken even. While the NBA has billion-dollar contracts with NBC and TNT, the WNBA has severely more limited financial agreements with Lifetime, NBC and ESPN.

Unlike many of the players who supplement their incomes by playing overseas during the offseason, Weatherspoon, 35, spends much of the time in the city doing promotional work and league appearances. The Liberty begin training camp on May 1.

Weatherspoon, who led the Liberty to the finals last season, said the league is considering extending its season, as well as adding new teams, possibly one in Chicago.

“We want to take on a new level, especially financially,” she said.

Weatherspoon said Notre Dame’s exciting victory against Purdue in the NCAA final last weekend is another boost to the women’s game. But there’s plenty more room to grow, she said.

“It definitely hasn’t reached its goal yet,” she said. “But we’re definitely reaching and we’re going to get there.”