Vikings General Manager Rick Spielman might be looking to trade.

During his pre-NFL draft news conference Tuesday at Winter Park, Spielman delivered one of his annual advertisements, noting that he is open to trade offers and asserting that the Vikings' phone lines have been buzzing.

"I'm telling you, it's been the most active it's been in a while," Spielman said. "Because of where we're picking. And I don't know the reason why, but there are a lot of teams that potentially are jockeying from the top of that second round and there are some teams jockeying potentially in the bottom of the first round to come up to one of our picks."

Even though Spielman is armed with picks 23 and 25 for Thursday's first round, the GM can't promise he'll use both, still exploring opportunities to move back and gather additional picks for either this year or next year.

"That's something we're going to be very open to," Spielman said.

Spielman said it's unlikely, however, that the Vikings would try to trade up in Round 1 on Thursday, particularly with a draft that seems to be loaded with depth at so many positions.

Linebacker options

The Vikings still have a vacancy at middle linebacker, a position they figure to address in some way this weekend. But Spielman said the team hasn't ruled out the possibility of turning veteran Erin Henderson loose as the starting middle linebacker in 2013.

It's not a shock the Vikings would leave that option open. But it would seem to be more of a last resort if the team struck out in finding a middle linebacker in this weekend's draft.

Henderson seems better equipped as a weak-side linebacker and was far from spectacular a year ago when playing middle linebacker in the Vikings' nickel packages. But Spielman asserted Tuesday that if the Vikings found an outside linebacker they really liked in the draft, they would be open to sliding Henderson inside.

"That's what is great about this linebacker thing," the GM said. "We have the flexibility to go either way."

Big Pat is back

The Vikings will sign Pat Williams to a contract Thursday. But no, there isn't any plan for Williams to supply depth at nose tackle. Instead, the one-day contract will be a symbolic gesture, allowing Williams to formally retire as a Viking.

The 40-year-old lineman started 93 games over his six seasons with the Vikings from 2005-10, anchoring a sturdy front that gave the team one of the league's most consistently stingy run defenses. His 14-year NFL career ended after the 2010 season.

Williams will participate in the team's draft party at Mall of America Field on Thursday night.