I wrote Tuesday about three potential Vikings problems for tonight’s Vikings-Saints season opener.

Now here are three issues the Saints might be facing for the game:

Linebacker weakness?

The Saints wanted Jonathan Casillas to win the job at weakside linebacker, and he beat out Jo-Lonn Dunbar for the job. They were impressed enough with Casillas that they moved Scott Shanle to the strong side because of Casillas’ play.

But that was before Casillas suffered a season-ending foot injury. That pushes Dunbar into the starting lineup on the strong side, with Shanle shifting back to the weak. Will all this shifting hurt them?

The good news is that Shanle is smart and versatile, so he should be steady. And Dunbar did take the majority of the first-team “Sam” snaps early in the summer. So it’s not as if either guy will be throw into unfamiliar waters. That said, it certainly stands as a position of concern. Keep an eye on Vikings TE Visanthe Shiancoe, who will be matched up at times with Dunbar, who is making his first start.

Malcolm Jenkins

The Saints like what they have seen from Jenkins, who is making his first start in place of Darren Sharper. With Sharper on the PUP list for at least the first six games, Jenkins is slated to take over.

He has cornerback’s coverage and ball skills, but the fact remains he is playing a relatively new position. And with coordinator Gregg Williams’ pressure-based system, Jenkins will find himself all alone in the center of the field in a lot of single-high looks. He also could come up and be asked to cover a fourth or fifth receiver, or perhaps blitz.

The Vikings will look to try to expose Jenkins on an island. Keep an eye on Bernard Berrian, who can get deep and had a nice game (9-102 receiving) against the Saints in the NFC title game. Jenkins might be able to handle the challenge, but it would be asking a lot for him to play at the same level Sharper did last season as a game changer.

Offensive line

Really, this unit did a lot of great things last season for an offense that was mostly outstanding. But you can say for certain that the Vikings’ defensive front is going to pose a serious matchup. Although the Vikings tallied only one sack in the NFC title game, they got a lot of pressure and Drew Brees had one of his lowest passing totals to go along with 14 incomplete passes in the game.

There’s a great matchup to follow with Vikings DE Jared Allen and Saints OLT Jermon Bushrod. Although Bushrod stepped up as the Saints’ starter last season and did a respectable job on Allen in the conference title game, Allen is an underrated student of the game who often pores over a teammate or opponent he faces for a second time. He makes sure to identify — and try to exploit — any weaknesses Bushrod might have shown on tape since then.

The Vikings are stout and deep all the way across, and the Saints don’t want to have to keep their backs and TE David Thomas home all night to pass protect. If they do, it takes one more weapon out of a passing route, which could be limiting.