He remained for his senior season because of unfinished business, but, to date, business hasn’t been as booming as hoped.

Through five games, Matt Barkley has a loss – Stanford might remain the unfinished business of his career – and statistics that lag behind what he did as a junior.

If the votes were counted today, Barkley wouldn’t be first team all-conference. He probably wouldn’t be second team, either.

There is, potentially, a worse development, one for which he owns no responsibility. Is it possible that USC’s quarterback brand in the NFL has been tarnished enough recently to impact Barkley’s draft value?

The pros are starving for quarterbacks, and Barkley seems to possess the necessary qualities to play in the NFL long-term.

But didn’t Matt Leinart possess enough of those same qualities to be a first-round selection? Didn’t the New York Jets believe so much in Mark Sanchez’s qualities that they traded two draft picks and three players to secure him in the first round?

Maybe it’s an overreaction or maybe it’s just the collateral damage done by the almighty power and wonder of Tebowmania, but Sanchez’s recent struggles and Leinart’s underwhelming pro career got us thinking:

Will NFL people look at Barkley – another quarterback from USC, another product of Orange County, another projected first-rounder – more harshly now?

A reach, you say? Perhaps, but it isn’t a reach to note that, similar to how quarterbacks build paper-tiger resumes playing in pass-happy systems, Trojans quarterbacks benefit from all the talent, particularly at receiver, surrounding them.

It’s not unlike the history of Duke basketball players in the NBA, collegiate stars who shine in a system loaded with skill but often struggle just to survive outside that system.

We write this knowing that Sanchez has won more road playoff games in the NFL than Joe Montana, Peyton Manning and Ben Roethlisberger, and that, on Monday night, he could beat the unbeaten Houston Texans.

But, as of right now, the discussion in New York concerns the strength of Sanchez’s psyche and whether or not the Jets ruined him by bringing in Tim Tebow.

Meanwhile, Leinart sits the bench in Oakland – behind another quarterback from USC and the OC, another first-rounder, Caron Palmer – having completed just 10 passes total since 2009.

This theory is based on guilty by association, which isn’t fair, but it is only a theory, folks. We know, for example, that Kyle Boller (in 2003) and Aaron Rodgers (2005) both were first-round picks out of Cal.

What Boller didn’t do in the NFL has had zero impact on everything Rodgers has done. We’re not saying this theory is air-tight, only that it is worth pondering as Sanchez’s reputation sits at a crossroads.

As noted above, this could all be the result of Tebow, and isn’t he The Answer to pretty much every football question? The NFL’s greatest all-time quarterback, at least among those who throw a football as if it’s an end table, is now proving to be a standout defender, too.

The media – oh, let’s just be honest here – ESPN is crediting Tebow with sacking Sanchez with his mere presence. The suggestion is that Sanchez is threatened or distracted by Tebow’s general awesomeness.

In case you haven’t heard this storyline, don’t worry. Leading up to kickoff Monday night, ESPN will dedicate the necessary hours, dollars and reporters to drive this idea so deeply into the ground that even the dead will know about it.

Whatever the explanation, the Jets’ offense has sputtered this season and, last week against San Francisco, produced four turnovers to zero points. Sanchez didn’t look good and, worst of all, he didn’t look mentally strong.

Neither of those things play particularly well in New York. If this season continues to sour on Sanchez, Barkley could conceivably be affected. Just another soft QB from SoCal, blah blah blah…

It’s not fair, but it doesn’t need to be fair. This is the NFL, as cut-throat and cruel a league as exists. When the NFL makes a decision on a player, that decision rarely becomes unmade. Ask Chad Johnson about that.

Barkley still has seven regular-season games, possibly the Pac-12 title game and a bowl to impress the NFL. He’ll have the draft combine and individual workouts to answer any doubters. The talent evaluators who interview him will be sold.

Perhaps, ultimately, there’s nothing to this theory. Barkley still could finish his business at USC and then really go into business for himself in the NFL.

But the subject is intriguing enough to consider, at least until Tebow decides what we should focus on next.

Contact the writer: jmiller@ocregister.com