The Vikings will reunite with an old friend on Sunday when Percy Harvin and the Jets come to TCF Bank Stadium. And while Harvin hasn't put up big numbers for his new team, head coach Mike Zimmer said that the Vikings have to be aware of where Harvin is at all times.

"They do everything with him," Zimmer said today. "They put him in the backfield as a back. They run reverses with him. They run screens with him. They run pretty much everything. He's definitely a focal point of what they're doing."

In five games with the Jets, who acquired him from the Seahawks in a stunning midseason trade, Harvin has caught 19 passes for 182 yards. He has also rushed for 96 yards on 17 attempts — a 5.6 yards-per-carry average. He is still looking for his first touchdown, though.

But his presence could potentially open up things for teammates such as former Gophers wide receiver Eric Decker if the Vikings are scrambling before the snap to figure out where Harvin is and where he will be going. The Jets are using Harvin in a variety of formations to try to create mismatches with personnel.

That's why Zimmer said that Harvin makes preparation more difficult for a defensive coordinator.

"We'll know where he is. It's the other guys, making sure we get the right matchups and everything else," he said. "They might have three backs and two receivers and he might be lined up as the back. They might have three tight ends and two receivers and he's the back. He can line up anywhere."

The last time the Vikings had to worry about Harvin was last season, when he was still with the Seahawks. He only had one catch for 17 yards as he made his return from an injury. But he had a 58-yard kickoff return in a Seahawks win. Harvin now returns kicks for the Jets, too.

The good news for the Vikings is that Harvin will at least be easy to find on those plays.