SANTA CLARA, Calif. — Mike Martz said today that he thought 49ers quarterback J.T. O'Sullivan was "remarkably further along" than what he expected heading into the season.

The offensive coordinator's assessment of his wide receivers, however, wasn't as rosy. He said their play was "rusty" in the opener against Arizona, the result of several receivers missing significant time in the preseason. Their routes weren't as precise and disciplined as they should be, Martz said. As a result, the timing was off in the passing game.

A case in point came in the first quarter when O'Sullivan tried to hit wideout Arnaz Battle and was intercepted by safety Adrian Wilson.

"The interception, we had a broken route," Martz said. "We didn't run the right route. The ball was thrown where it needed to be thrown. So obviously that wasn't (O'Sullivan's) fault." O'Sullivan completed only four passes to his wide receivers three to Bryant Johnson and one to Battle.

Still, Martz said he saw plenty of positives against the Cardinals, and the statistics back up his assertion.

The offense averaged 6.61 yards per play against Arizona. Only five teams — all of them winners — had a higher average in Week 1. San Francisco also finished with 291 yards of offense, a mark it surpassed only twice last season.

The problem was five turnovers and the fact that the 49ers had the ball for only a little more than seven minutes in the second half.

Martz, however, said O'Sullivan, who was making his first regular-season start, didn't deserve much blame. The only turnover for which he was responsible came at the end of the game when he was sacked by Travis LaBoy and fumbled.

"So there's really one play in there where he might have been ... just a little careless with the ball," Martz said. "Those other two (turnovers), we need to go elsewhere in terms of fixing."

Martz said he was especially happy that O'Sullivan didn't try to force any plays, a tendency that got him trouble early in the preseason.

"That's disappeared," he said. "So those are the things that the coaches are getting excited about."

In contrast to Seattle, which practiced without its three top receivers Thursday, the 49ers are remarkably healthy. Center Eric Heitmann (shoulder) and cornerback Donald Strickland (knee) did not practice but are expected to be ready Sunday.

The Seahawks are welcoming back defensive tackle Rocky Bernard, who served a one-game suspension last week. Bernard, of course, separated Alex Smith's shoulder on a sack early in the team's first meeting a year ago.

Martz has said in the past that O'Sullivan compares favorably to the notable quarterbacks like Kurt Warner and Marc Bulger that he's coached in the past. Today, however, Martz said O'Sullivan was more mobile than his former pupils.