An ominous sky over TCF Bank Stadium makes me think Grantland Rice should be writing the lead to this blog … tornado watch is in effect as the Vikings meet the Raiders tonight at 7.

The Vikings have mentioned in their pregame literature that fans will be directed to Williams, Mariucci or Ridder Arenas in case a storm disrupts the game. There will probably be a few folks watching the radar closely.

Anyway, on the game. The Vikings are 2-0 and the Raiders 1-0, so something has to give.

The Vikings’ focus offensively tonight will likely be on its offensive line, which lost right tackle Phil Loadholt (Achilles’ surgery) for the season. Rookie T.J. Clemmings will be the starter at right tackle on Saturday night at TCF Bank Stadium when the Vikings met the Raiders in a preseason game.

Rookies Tyrus Thompson and Austin Shepherd will also get a long look tonight on the offensive line.

The Vikings, who played in the Hall of Fame game, have an extra preseason game, which coach Mike Zimmer has lauded.

“I think it’s good for all of the young guys, because they’re going to continue to get some more playing time, another chance to evaluate and … we get a chance to tweak some things around and look at some guys with different people,” Zimmer said Thursday.

Although the Vikings can’t really afford another injury on the offensive line, Zimmer said, “We’re not going to get gun shy because something happens. We’re going to continue to work and obviously, we’re going to be smart about it. We have to get what we need to get accomplished for the season.”

During the regular season, team usually have seven offensive linemen active, so the two spares have to be versatile. That might be a key for players trying to make the team.

“We’re looking for starters and then we’re looking for backups, but … guys that can play both sides, so we can dress one less on game day.”