Being a backup quarterback in the NFL is one of the hardest jobs in football.
We know this because the Bears went out of their way last week to explain to us that being a backup quarterback in the NFL is, well, one of the hardest jobs in football.
See, the backup doesn't get many reps during the week because the starter is spending his time with the first unit, so the No. 2 has to be ready to step in at any moment prepared to play even though he hasn't had much work.
He has to know all the calls, all the assignments and think just like the starter in case he becomes the starter, which can happen at any moment.
That sounds very much like the definition of a backup quarterback in a league where starters get hurt every week.
Yet, Jason Campbell looked unprepared when he relieved Jay Cutler against Houston. He was awful in the second half, save one throw on which Brandon Marshall made a spectacular catch in traffic.
Thing is, the Bears told us the signing of Campbell in March was a huge part of their off-season, with GM Phil Emery insisting "that it's difficult to see anybody in the league topping that in terms of positive experience at the (quarterback) position."
And again in April, when Emery said, "We want to go into the season knowing that if something were to happen to Jay that we have a quarterback … we can still win a championship (with), and we really believe we have found that in Jason Campbell."
They said it again in June, July and August, and now they've been saying it the last few days even though Campbell got off to a rough start.
In June, Campbell said, "I've been through learning new offenses a couple times, so that part I've already adapted to. I'm just trying to learn this new role, understanding that a lot of what you do is going to come from the classroom and mental reps more than physically getting reps."
Maybe he wasn't doing those mental reps because now Campbell says, "I've been staying up all night and days studying film and making sure I can catch up for the time that's been lost. You know you can't get all that time back but try to mentally know exactly what you're doing."
In fairness, it is a tough spot. But at $3.5 million this season, Campbell is the highest paid No. 2 who went to an NFL camp strictly as the backup quarterback.
With Cutler missing games the last two years and the Bears 2-5 in those games, Emery was smart to search for a legit No. 2, something Jerry Angelo never bothered to try.
Angelo wasted so many years that he had enough time to draft and develop another quarterback, but with the Bears needing to win now, free agency was the only way for Emery to go.
"Our combination of Jay Cutler, who's our leader, Jason Campbell and Josh McCown," Emery said in March, "is tough to beat in the NFL."
Emery believed that in part because of Campbell's 70 career starts. He was certain Campbell had the ability to step right in and play.
"They expect a lot of out of you," Campbell said, "because this is the reason they bring you here as a backup."
The Bears will face in San Francisco the third-ranked defense in the NFL, and Mike Tice is going to need to call NFL plays, not the high school plays he tried to run last Sunday for a shaky Campbell.
The Bears made a lot of excuses for Campbell last week but Monday night they need him to play like the veteran, NFL starter they signed in March, not the guy who showed up last Sunday night.
It was only one half of a football game, and we suspect Campbell will be much better Monday night after a week of practice.
Emery said they could win a championship with Jason Campbell. That might not be necessary, but with Cutler's status up in the air, they do need Campbell to perform like a competent NFL quarterback for at least a game and maybe more.
If that's asking too much, they better ask someone else.
•Hear Barry Rozner on WSCR 670-AM and follow him @BarryRozner on Twitter.