SAN ANTONIO (AP) — The still-scuffling US economy may keep some NBA teams from starting the season with full 15-player rosters, according to a survey of all 30 franchises by The Associated Press.

With the season opening on Tuesday and final rosters due on Monday, the survey found that nearly half the league plans to start with 15 players. But others will carry the minimum 13 or leave one spot empty.

Chief among the reasons was flexibility – having an available spot or two to keep options open for trades or injuries in the long, 82-game season. No teams outright said their decision would be driven by the economy, but the bottom line is clearly an issue.

“NBA teams are businesses like every other in this country,” Dallas Mavericks owner Mark Cuban wrote in an e-mail to AP. “Times are tough and I expect many if not most teams to carry fewer than 15 players on their rosters.”

NBA teams are allowed to carry 12 active and three inactive players. Not filling all 15 slots would not leave a team at less than full strength for games, though it might leave it short-handed for practices.

The Denver Nuggets will start with a 13-player model after going with 14 last season and the full 15 in the two seasons prior.

In the first seven games last season, the Nuggets used more than nine players only once. Mark Warkentien, the team’s vice president of basketball operations, said he likes having chairs open at the end of the bench, just in case.

“There’s an obvious economic benefit. I’m not going to deny it,” Warkentien said.

The minimum NBA salary this season is about $457,000 for rookies.

The luxury tax threshold is about $70 million, meaning teams must pay a $1 tax for every dollar spent on salaries above that limit in a given year.

Expectations by coaches and general managers for their roster sizes this season are generally in line with previous years. Los Angeles Clippers general manager and coach Mike Dunleavy, for instance, said he’s carried 15 players for the past few years – 14 with guaranteed contracts – and expects the same again for this season.