With the long hours, intense game-day pressure, and Monday-, Tuesday- and every other day that ends in Y-morning quarterbacking, Bill O'Brien earns the money he is being paid as the Texans' head coach.

I imagine the over-the-shoulder quarterbacking is more difficult to ignore when Bob McNair, the man who signs the checks, pulls up in a golf cart, as he did at Monday afternoon's practice.

Not that it is unusual for McNair to leave his office at NRG Stadium to venture across the street to watch his team's workout, but this is a special week - nay, a holiday week.

O'Brien has been with the Texans for 10 months - nine games, five losses and four wins - and the honeymoon is far from over. But on Sunday, McNair should get a better sense if the man he hired can get the job done.

Problem still unsolved

When you hire a mathematician and throw him a math problem, you expect him to solve it.

While the Schaub Shambles and the Keenum Quandary weren't exactly the Poincaré Conjecture, the Texans had a quarterback problem. O'Brien was hired to solve it.

The problem remains unsolved. Thus, we're celebrating Quarterback Change Week. Again.

Time to go bury another QB's jersey. Oops, that was a typo. Make that buy another Texans QB jersey.

O'Brien's initial solution to the team's quarterback problem was Ryan Fitzpatrick.

E did not equal MC2.

Sunday in Cleveland, O'Brien will insert Ryan Mallett into the equation.

How Mallett performs over the next couple of months could be a testament to O'Brien's excellent coaching ability. Or evidence that his talent-assessment skills are lacking.

Whatever happens, the Texans would be best served not to allow Mallett's performance to convince them that drafting a quarterback isn't a priority.

Must draft a QB

Unless rookie Tom Savage shows surprising growth and development, the miscalculation with Fitzpatrick might already have set the franchise back a year in filling the most important position in team sports.

The Texans spent $2.5 million more in guaranteed money on Fitzpatrick than the Eagles did on Mark Sanchez, who came off the bench a little over a week ago to lead the Eagles to a win over the Texans. In his first start with Philadelphia on Monday night, Sanchez threw for more yards (332) without an interception than Fitzpatrick ever has.

O'Brien wanted Fitzpatrick that much. He didn't want any of the quarterbacks in the draft enough to take one in the first three rounds. He kind of, sort of, basically, pretty much, for the most part wanted Mallett.

O'Brien saw Mallett every day in practice for the entire 2011 season with the Patriots, but he didn't think enough of him to pay the price to get him in a trade during the offseason. The Texans finally agreed to send New England a late-round draft pick for Mallett at the end of the preseason, when they no longer wanted Case Keenum around.

Mallett, a 6-6 statue once thought to be a first-round talent, slipped in the draft because of off-the-field issues and questions about his attitude. But he might have the strongest arm in the NFL.

That arm will be on display in a real game for the first time in years, since Mallett has been a backup with mop-up duty for 31/2 seasons. He has taken a knee twice as many times as he has thrown a pass.

Molding Mallett

Can O'Brien make something of Mallett, who the Texans say looks good in practice?

For someone with so little time as an offensive coordinator or a quarterbacks coach, O'Brien has a reputation of being an outstanding offensive coordinator and quarterbacks coach.

As for his NFL résumé, he still has a lot to prove.

Oh, he was the quarterbacks coach and de facto offensive coordinator for New England in 2009 and '10 and the official offensive coordinator there in 2011, when the Patriots led the league in points, were second in yards per play, and committed the fewest turnovers.

Not coincidentally during that stretch, New England tied New Orleans for the most regular-season wins.

But the Patriots had Tom Brady on the roster.

Not to minimize O'Brien's contribution, but signing on as the Patriots' quarterbacks coach in 2009 was akin to becoming Picasso's painting instructor just after he finished "Guernica."

For all we know, particularly compared with Brady, Mallett is a finger painter. He has thrown only four passes in his career, completing one to a teammate and one to a defensive back (former Texans safety Shiloh Keo).

"He's very, very excited, and we're looking forward to seeing what he can do," O'Brien said.

We'll assume O'Brien knows more about what Mallett can do than he is letting on. After all, he is paid to know.