PHILADELPHIA (973espn.com) - The calendar turned to April on Monday and from the NFL perspective that is sort of the demarcation line where free agency officially takes a back seat to the draft.

Of course, there is plenty of multitasking that goes on and the Eagles are well into their Top-30 visits as the final piece of the puzzle following the Senior Bowl, the combine and the various pro days around the country,

Many observers put more stock into top-30 visits than they probably should especially when it comes to top of the draft options because certain teams are trying to obfuscate interest in a potential first-round target. What the invitations do confirm, however, is an interest in having questions answered from certain prospects and those queries can be positive or negative.

One organization even used to use a large portion of its top-30 visits to get a leg up on players they thought would end up as priority undrafted free agents, using it as a recruitment tool.

Probably the more important aspect of top-30 visits is the ability to glean where an organization feels they may need a little more help, something you can see if patterns develop at certain positions.

In the Eagles case we've been able to ascertain 15 visits so far through various reports and there has been a clear effort to look at the offensive line, defensive backfield, particularly safety, and the defensive line, which is no secret because Howie Roseman called the 2019 draft class "historic" at that position.

Up front on offense Boston College guard Chris Lindstrom, tackle prospects Cody Ford of Oklahoma, Tytus Howard of Alabama State, Brandon Hitner of Villanova and interior pospect Hjalte Froholdt of Arkansas have been to South Philadelphia. If you cross-reference that a little bit, you'll notice that offensive line coach Jeff Stoutland was really hands-on with both Lindstrom and Howard at their respective pro days.

The biggest splash came on the defensive line with Houston's El Oliver, the generational athletic talent who looks like a John Randle-type interior rusher but has some teams looking at him at defensive end or even linebacker because of his movement skills. Oliver is among the most polarizing players in this class but his physical gifts are so strong it's hard to imagine him falling to anywhere near No. 25 at this point.

Others brought in to date are a couple of edge players, TCU's L.J. Collier and Old Dominion's Oshane Ximines while Mississippi State's Montez Sweat, a potential top-10 pick, is scheduled for this week.

The defensive backfield talent given free t-shirts so far include three safeties: Maryland's Darnell Savage, Florida's Chauncey Gardner-Johnson and Virginia's Juan Thornhill. Penn State's Amani Oruwariye and Oliver's teammate at Houston, Isaiah Johnson, were the corners getting a tour of NovaCare.

Rounding out the list of visits are two skill-position prospects: Michigan running back Karan Higdon and Ole Miss receiver A.J. Brown.

Of the names in so far, the top-of-the-draft types are Oliver, Ford, Lindstrom, and Brown. Of those names, Oliver and Ford will likely be out of reach but Lindstrom and Brown are realistic options at No. 25.

Beside Stoutland, Eagles' assistants who have been hands-on at certain pro days include RB coach Duce Staley, who was at Alabama to look at Josh Jacobs, another possibility at 25, and Damien Harris, Miami-Florida to put Travis Homer through the paces, and Memphis where Staley looked closely at both Darrell Henderson and Tony Pollard.

New defensive line coach Phillips Daniels has also had quite the itinerary and got up close and personal with UCF defensive tackle Trysten Hill and also made the time to break bread with injured Mississippi State DT Jeffrey Simmons, a first-round talent who is recovering from a torn ACL.

If you're reading tea leaves Stoutland's interest is usually genuine. He's a no-nonsense guy who isn't in to playing games and worked extensively with both Matt Pryor and Jordan Mailata before last year's draft.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen