The 49ers and their fans are sweating the offense, wondering if Michael Crabtree can give it some juice, hoping coordinator Jimmy Raye can summon creativity from a mind more comfortable with basics.

Nate Clements, for one, ought to be thankful.
The curiosity about Crabtree, the obsession with fixing a stagnant running game and a deficient offensive line fosters a climate that at least partially obscures the shortcomings of the cornerback who arrived in 2007 on a vessel of hype crafted from his sterling reputation and the staggering contract negotiated by his agent.
Clements’ $80 million ($22 million guaranteed), eight-year deal — since adjusted to $64 mil for seven years — made him at the time the highest-paid defensive player in NFL history. His play through 37 games as a 49er has not measured up to salary.
The latest example is Nate’s last game, Oct. 11 against Atlanta, when wide receiver Roddy White enjoyed a career day: eight catches, 210 yards, two touchdowns. As astounding as the overall numbers are, the most disturbing sequence for the 49ers and for Clements was the way White finished his 90-yard touchdown. After catching a short pass in front of Clements, White spun out of a tackle and dashed away like a cheetah outrunning a bloodhound.
Any fine, instinctive 29-year-old cornerback who loses ground in a chase is counting the minutes until he becomes a safety. White’s performance was reminiscent of Terrell Owens’ masterpiece last November. Then with the Cowboys, T. O. roasted the Niners, mostly Clements, for seven catches and 213 yards and a touchdown.
There are the other instances in which Clements is shown in unflattering light, such as San Francisco’s Sept. 27 loss at Minnesota. The Vikings scored first when a 49ers blitz left Clements in coverage against wideout Sidney Rice. Brett Favre spotted the matchup and burned the blitz on a 30-yard hookup with Rice. This is unbecoming of a cornerback whose Web site is “Lockdown22.com.” Yet it made sense for the 49ers to pursue and sign Clements. They had enough salary cap space to hide a fleet of yachts, they needed a quality corner and Clements was by all accounts the best available free agent.
The presumption was Clements would be the best cover corner in a San Francisco uniform since Deion Sanders’ one-year mercenary mission in 1994.
But legitimate shutdown corners intimidate even the best quarterbacks, persuading them to do the smart thing and throw to the other side of the field.
There is nothing to indicate passers fear throwing at Clements.
Which means the 49ers’ defense, while improving, still has a hole — especially when the pass rush is slowed. There is no shutdown corner, meaning the entire field is in play for the quarterback. The Falcons, with two weeks to prepare, saw that and exploited it.
It’s reasonable to think Houston, which plays host to the Niners on Sunday, will do the same. Texans coach Gary Kubiak is offensive-minded, Matt Schaub is a quality quarterback and Andre Johnson is one of the five best wideouts in the NFL.
If Clements were a true shutdown corner, defensive coordinator Greg Manusky could rely on Nate to contain Johnson, forcing Schaub to look elsewhere. It worked for the Jets, who in a 24-7 win last month held Houston to 183 yards. Covered mostly by Jets cornerback Darrelle Revis, Johnson was limited to four catches, for 35 yards.
Revis the following week was primarily responsible for holding New England’s Randy Moss to four catches, for 27 yards in a 16-9 win over the Patriots.
Thus is illustrated the value of a shutdown corner. Revis is a member of an elite fraternity, along with Oakland’s Nnamdi Asomugha, Denver’s Champ Bailey and several others.
Clements is beaten too often and too badly to be among them.
This is not about whether Nate is a good guy. He certainly seems to be, on and off the field. It’s not about whether he’s a good player, either. He is instinctive, dedicated and among the league’s most physical corners, whether jamming a receiver cutting down a runner. Any general manager in the NFL would be happy to have him.
The 49ers surely are happy Clements is on their roster. He’s the best they have.
And it’s a lot easier to cast him as such when fires are raging elsewhere, diverting attention toward the punchless running game and the leaky offensive line and the shiny new toy to be unveiled Sunday.