Prior to next month's draft, the Patriots (and every NFL team) are entitled to 30 visits with players that will take place at the team's facility.
The visits do not include any on-field work, but they give the team an opportunity to have prospects further evaluated by their own medical staff, and members of the coaching and personnel department get the chance to interact with the player in a unique setting.
During my time in Kansas City, I recall these player visits as being a unique part of the scouting process because the players each approached them in a different manner. Some chose to show up in a suit and treat the day as a job interview, while others felt the day was a more casual affair. (Among the memorable moments was taking Rob Gronkowski around for the day and having coaches remark that his hands were bigger than any other prospect's that they could recall).
The visits take place for many reasons, and teams invite players that they have varying levels of interest in. Moreover, many teams draft players that never enter the facility at all. The Cowboys had no pre-draft interaction with cornerback Morris Claiborne prior to selecting him in the first round last year, as an example.
The take-home point is this: On-site visits are a part of the scouting process, and teams invite players for different reasons. In some cases it is because they feel they are interested in that player and he could be available for one of their selections, and other times visits are simply to learn more about a player they don't have extensive information on.
Two of the Patriots visits have been identified, as both running back Marcus Lattimore of South Carolina and cornerback Tyrann Mathieu of LSU will visit the team in April, according to reports from Robert Klemko of USA Today and Jeff Howe of the Boston Herald.
The pair of prospects are among the more notable in the draft class this year, as each had their college career end early for different reasons. Lattimore is coming back from a gruesome knee injury, while off-field issues kept Mathieu off the gridiron this past fall.