Illinois held their Pro Day on March 6th, and the Patriots were one of 29 NFL teams in attendance. According to Dan Pompei of the Chicago Tribune, the Patriots paid particular attention to defensive end / outside linebacker prospect Whitney Mercilus:
Among those present was New England Patriots college scouting director Jon Robinson, who usually is the member of the front office but who evaluates defensive ends who are trying to play linebacker.
There were no general managers, head coaches or defensive coordinators at the workout, but there was a good showing of area scouts. There were 34 NFL representatives from 29 teams.
Front office personnel members such as Robinson, Bill Belichick, Nick Caserio, Jason Licht and others will all be making the rounds to different college Pro Days, so this wouldn't qualify as "big news."
However, it is notable that the Patriots had one of their top personnel evaluators in attendance, considering that Mercilus is regarded by many as a top DE/OLB prospect, expect to go in the late first round.
Other notable players performing at the Illinois Pro Day included A.J. Jenkins, a speedy wide receiver expected to go in the middle rounds of the draft, and Tavon Wilson, a late-round prospect who is a bigger cornerback who could be a safety conversion.