SAN ANTONIO ? There was plenty of second-guessing Thursday at the NBA Finals, most of it centered around Nets coach Byron Scott, New Jersey forward Kenyon Martin and the defensive strategies against San Antonio’s Tim Duncan.

The questions were all valid; the answers spoke volumes.

l Why did Scott leave Martin on the bench for 71/2 minutes in the second half after he picked up his fourth foul?

“I talked to Kenyon and he didn’t know why he was sitting there,” Jason Kidd said.

l Why didn’t Scott send more double-teams at Duncan when Martin was on the bench?

“That’s not our game plan, to come out and double him right off, but if (Duncan’s) got it going, a fool wouldn’t do it,” Martin said.

l Why didn’t Dikembe Mutombo get a chance to defend Duncan in the second half?

“It is surprising that they don’t have him in their rotation,” Duncan said.

Plenty of the second-guessing was coming from the Nets themselves, who curtly answered “Ask the coach” when questioned about strategy.

Nets guard Jason Kidd talks at a news conference. Kidd spoke Thursday in San Antonio.

Scott conceded he had begun thinking about giving Mutombo a bigger role, but said he had no regrets about leaving Martin on the bench for so long in the third and fourth quarters.

“I went over the tape last night and this morning,” Scott said. “I still feel the same way.”

With Game 2 of the best-of-seven series scheduled for 7:30 tonight, there will be plenty of focus on the adjustments Scott makes — or whether he makes any at all.

After all, this is the same coach who refused to double-team Shaquille O’Neal until Game 3 of last year’s finals.

He’s also the same coach who raised the white flag against the Lakers in Game 4, pulling Kidd and Martin off the floor with 44 seconds remaining and his team trailing by only six points.

“As far as adjusting, just looking at the tapes, the three things we talked about doing we just didn’t do a real good job of doing,” Scott said. “Our pick-and-roll defense has to be better, our post defense has to be better, our pressure and containment has to be better.”

New Jersey’s offense has to be better, too, but that won’t really matter if the Nets can’t find a way to contain Duncan.

Spurs coach Gregg Popovich, right, talks with players Tim Duncan, middle, and David Robinson. The Spurs practiced Thursday in San Antonio.

The league’s MVP had 32 points, 20 rebounds, seven blocks and six assists, although the Nets did manage to hold him to two points in the first quarter when Martin defended him one-on-one.

But in the second half, Martin went to the bench with 2:28 remaining in the third quarter. He stayed there until 6:56 remained in the game, with Duncan scoring nine points in Martin’s absence as Rodney Rogers and Aaron Williams were helpless to stop him.

“I did kind of expect (Mutombo) to come in and play a little bit more,” Robinson said. “When you’ve got a big 7-foot-3 guy on the bench, it’s kind of nice to be able to bring him in.”

Rogers gives up five inches to the 7-foot Duncan, while Williams is three inches shorter. Duncan did as he pleased against them, from setting up deep in the low post to popping outside for jump shots.

All the while, Mutombo — a four-time defensive player of the year — sat and watched.

“I was brought in to help the organization win a championship. We’re playing for a championship, but I’m sitting on the bench,” Mutombo said. “You should go find that man and ask him.”

Might Mutombo, who is making $14 million this season and is under contract for two more years, try to speak to Scott about it face-to-face?

“No, we don’t talk,” Mutombo said.

The other part of the problem for the Nets was their offense. New Jersey was unable to execute its fast break and couldn’t find anybody who could make a shot in their half-court sets.

Kidd was 4-for-17 from the field as New Jersey shot just 37 percent to offset its advantages in offensive rebounding (13 to the Spurs’ 10) and turnovers (The Nets committed eight to San Antonio’s 12).

The Spurs usually don’t play a zone defense, but they threw one at the Nets on several occasions and stifled them.

“They didn’t shoot the ball well. It sounds simplistic, but they busted their butts as hard as we did. We knocked down more shots,” Spurs coach Gregg Popovich said.

There have been only seven sweeps in the history of the NBA Finals, but only two coaches who are completely winless in championship-round games.

One is Brian Hill, whose Orlando Magic were swept by Houston in 1995.

The other is Scott, whose finals record is now 0-5.

Wednesday night’s game produced an overnight television rating of 8.1, down 37 percent from the Lakers-Nets matchup of a year ago.

The game was odd in that the first half was more competitive and compelling than the second, and the Nets’ performance in the final 24 minutes was so underwhelming that there’s already talk in this town of whether the Spurs might sweep.

If so, someone pointed out to David Robinson, then tonight would be the last home game of his career.

“I had not thought about it until you just mentioned it,” Robinson said. “Now I’m getting kind of sad.”