SAN ANTONIO - The Rockets don't plan to be as shorthanded as they were Friday night, when they left four starters in Houston. But they will be shorthanded to start the season Wednesday and likely for the first month.

Rockets coach Mike D'Antoni estimated point guard Pat Beverley could miss as many as 20 games because of the irritation in his left knee. Beverley is weighing whether to undergo arthroscopic surgery, but a person with knowledge of the situation said the timetable for Beverley's return is roughly the same if he has the surgery or doesn't.

Unlike Friday's game, when James Harden, Trevor Ariza, Clint Capela and Eric Gordon were rested, Beverley will be the only Rocket expected to be unavailable when the regular season opens in Los Angeles against the Lakers. But with the second unit starting Friday, the Rockets ended the preseason with a 114-99 loss to the San Antonio Spurs that could not have bolstered confidence about the team's depth.

That could be especially true with Gordon starting, rather than working as sixth man off the bench.

"It complicates things," D'Antoni said. "I hate it for Pat first of all. He worked so hard to get ready and his weight was great. On one hand, I hate it for him. On the other hand, I hate it for us a lot. The first 20 games, like I said 1,000 times, are tough. It would be nice to have him. But he'll be back. We'll make sure he's healthy."

Brown makes his case

The Rockets' issues against San Antonio likely were to be expected with the Spurs treating the game as a dress rehearsal and close to full strength with the exception of guard Danny Green who's out for three weeks. But other than Nene, the Rockets' starters Friday - Corey Brewer, K.J. McDaniels, Tyler Ennis and Ryan Anderson - went a combined 9-of-30, and that was with McDaniels finishing with a late-game flurry with the benches cleared.

Guard Bobby Brown, in his most extended and impressive playing time of the preseason, had 23 points and nine rebounds in what he hoped would be a final statement as the Rockets consider their final roster spot following a 5-2 preseason.

"We still have to find guys that can contribute … the seventh, eighth, ninth guy," D'Antoni said. "We can't have one night you can, one night you can't. I can't guess who's going to play well every night. We have to get guys more steady."

McDaniels and Sam Dekker likely have played their way into the rotation, but both have been "up and down" in the preseason. Both were more solid in the second half, but McDaniels in particular will be counted on, given his ability to defend point guards with Beverley out.

"He didn't play very good today," D'Antoni said. "He's up and down. He has to smooth it out. I told him the other day, he can't play great one day and bad two days and great one day. It doesn't work like that. I don't know when those good days are. We can't afford that. You can't have that drop-off."

Essentially a rookie

McDaniels will be helped by playing with more of the regulars, but said, "We do have to be better in ways, shot selection, me, finding the right people because I know help is coming. I have to do a better job."

McDaniels and Dekker have made strides, enough to for the Rockets to count on them. But the two played so little last season that both could be expected to have to learn on the job.

"Our coaches are so good, they know we're going to have growing pains," said Dekker, who played in three games as a rookie. "We're going to do stupid things at times. But we can make up for those plays by making three, four, five really good plays in a row. It's all about getting better, being in the film room, studying the game.

"I was talking to coach (Jeff) Bzdelik the other day. He looked at me and smiled and said, 'Don't put pressure on yourself. This is basically your rookie year.' It was good to hear that, get that reassurance from him."

Still, the Rockets will welcome the starters - minus Beverley - at Sunday's practice, which could even help the backups who struggled without them.

"Overall, we had a good preseason," D'Antoni said. "It's time to get serious. We're back to real stuff."