Tristan H. Cockcroft offers sound analysis on Greg Jennings' arrival in Minnesota, both from a fantasy and conventional standpoint. In short: Jennings will do more for quarterback Christian Ponder than Ponder will do for Jennings.
Here is how Cockcroft put it: "Jennings gives the Vikings a much-needed outside receiver, but his fantasy upside is worse in Minnesota than Green Bay, despite the lack of competition for targets. And let's not overlook this fact, lest we dive into overdrafting him: Jennings has appeared in just 21 of 32 scheduled games the past two seasons combined. He's actually more likely to give Ponder a fighting chance of keeping his job than Ponder is to feed Jennings the ball often enough to be a top-shelf fantasy option."
There are plenty of ways to be of fantasy value, but for a receiver, the easiest might be to have a quarterback who excels at throwing the deep ball. Last season, according to ESPN Stats & Information, Packers quarterback Aaron Rodgers completed nearly four times as many passes of more than 20 yards than Ponder. Also, Ponder joined Arizona Cardinals quarterback John Skelton as the only qualified quarterbacks not to throw a single touchdown on such throws.
Wide receiver Percy Harvin was the Vikings' leading pass-catcher before his season-ending ankle injury in 2012, but from a fantasy perspective, it's worth noting that he had only three receiving touchdowns among 82 targets. After his injury, as the chart shows, Ponder's top target was tight end Kyle Rudolph. Ponder threw only three touchdowns to wide receivers over that span.
So even if Jennings supplants Jarius Wright as the Vikings' most-targeted post-Harvin wide receiver, it's difficult to make much of a fantasy projection for him. Jennings can give the Vikings everything they want and still be a fantasy afterthought in Minnesota.