He leaves Happy Valley as a two-time Big Ten receiver of the year and was one of the best wideouts in school history. Former Penn State All-Americans Kenny Jackson and O.J. McDuffie previously told ESPN.com that Robinson belonged in the same elite group as them.
Robinson -- widely considered a second- or possibly a late first-round draft pick -- was easily the most valuable player on the Nittany Lions the past two seasons. He ended his junior campaign with a school-record 97 catches for 1,432 yards and six touchdowns. He accounted for a little more than 46 percent of PSU's yards through the air while finishing with more catches than the team's Nos. 2, 3, 4 and 5 receiving targets combined.
"It was a great honor to play at Penn State," Robinson said in a news release. "I am blessed to have played with, and for, the people in the Penn State football program. This is a decision that I believe is best for my family and I, and I wish all the best to the university and all my teammates."
Neither Robinson nor his family immediately returned messages seeking comment, and Robinson hung up when reached Tuesday night. As a result, it's not clear just how much of a factor Bill O'Brien's departure was in Robinson's decision -- but it certainly wouldn't be a surprise if it pushed him over the edge.
Robinson tweeted on New Year's Eve, prior to news leaking out to media outlets about O'Brien: "Welp, it's been real."
A recent mock draft has Robinson going No. 26 overall to the Cleveland Browns. And at least one former receiver thought A-Rob should leave for greener pastures all along.
"Allen Robinson, do me a favor," said Jackson, arguably the top wideout in PSU history. "You deserve to go the NFL, and you deserve to have someone pay you for what you've done at Penn State. You've made them a lot of money -- and you've given Penn State something to cheer for."
Robinson's departure is obviously not good news for Penn State's passing attack. Penn State will also be without No. 2 wideout Brandon Felder, who will graduate, and that leaves several unproven players to vie for starting jobs.
The Nittany Lions' returning leading wideout will be rising redshirt sophomore Geno Lewis, who finished the year with 18 catches for 234 yards. Penn State might find an option among one of its top incoming freshman wideouts -- if they stay committed -- but this position will certainly be a concern moving forward.