On the first day of NFL free agency last week, New England Patriots fans were all atwitter.

In a span of hours, the Patriots lost wide receiver/punt returner Danny Amendola to the Dolphins, cornerback Malcolm Butler and running back/kick returner Dion Lewis to the Titans, and left tackle Nate Solder to the Giants.

Twitter exploded. Patriots fans were bewildered: How can this be happening? What is Bill Belichick doing? When are the Patriots going to make a move? What’s Tom Brady thinking? Is this the beginning of the end?

It was obviously a frightening time to be a Patriots fan.

Since that initial flurry of defections, the Patriots have regained their footing. They signed a pass rusher (Adrian Clayborn, 91/2 sacks last year with the Falcons) and a power running back (Jeremy Hill, 29 rushing touchdowns in 54 career games for the Bengals). They re-signed elite special teams players Nate Ebner and Matthew Slater, along with versatile running back Rex Burkhead. They traded for an interior run stuffer (defensive tackle Danny Shelton of the Browns), a seasoned cornerback (Jason McCourty, another ex-Brown, and the twin brother of Patriots safety Devin McCourty) and the NFL’s most dangerous kick returner (Cordarrelle Patterson, a former Raiders wide receiver).

That leaves one very big question for the defending AFC champs: who’s going to play left tackle?

Yes, there are other needs – backup quarterback and tight end looming large – but the Patriots have to address their vacant left tackle position first.

Brady is going to be 41 when the season begins and has never been nimble afoot. Since 2001 (with a few exceptions because of injuries), his back side has been protected by either Matt Light or Solder.

The Patriots weren’t going to match the Giants’ four-year, $62 million contract offer to Solder. There doesn’t appear to be anyone in place on the roster to take his spot, although Marcus Cannon could slide over from right tackle. But Cannon is much more effective on the right side.

The Patriots have always excelled at finding replacement players. But where do they look this time?

There aren’t a lot of options in the free-agent market. The best two remaining free agents played for New England last year: LaAdrian Waddle and Cam Fleming. They played well in Cannon’s absence, but neither is likely the long-term answer.

Most likely, Solder’s replacement is going to come in the NFL draft. Belichick has never been shy about drafting offensive linemen; he’s selected 28 in his time with New England. In fact, his first draft pick as head coach of the Patriots was an offensive tackle: Adrian Klemm out of Hawaii in the second round of the 2000 draft (the Patriots lost their first-round pick that year to the New York Jets as compensation for signing Belichick).

OK, that one didn’t work out. But Belichick has taken two offensive linemen in the first round – guard Logan Mankins out of Fresno State in 2005 (32nd overall) and Solder out of Colorado in 2011 (17th overall) – and both turned out pretty good. Light was a second-round pick in 2001 (48th overall) out of Purdue.

You can expect the Patriots to use one of their first three picks – 31st in the first round, 43th (from San Francisco in the Jimmy Garappolo trade) and 63rd in the second – on an offensive tackle.

There are some intriguing prospects: Notre Dame’s Mike McGlinchey, UCLA’s Kolton Miller, Oklahoma’s Orlando Brown (son of the late NFL tackle Orlando “Zeus” Brown), Texas’ Connor Williams and Pittsburgh’s Brian O’Neill.

McGlinchey and Brown are projected as first-rounders. Miller’s prospects have risen and he could go in the first round. Williams is coming off a left knee injury that limited him to five games as a junior (his final season) at Texas. O’Neill is an intriguing option, an athletic tackle with good speed and run-blocking ability.

If the Patriots don’t get any of the top tackles, they’ll look to fill from within. But the options are limited. New England did sign veteran free agent Matt Tobin from Seatttle. He has 21 career starts and could fill in for a little while, but his role has always been as a swing tackle, and that’s probably where he fits best here. There are also a couple young tackles on New England’s roster: Cole Croston, an undrafted free agent last year from Iowa, and Tony Garcia, a third-round pick last year who missed the entire season after reportedly developing blood clots in his lungs.

Most certainly, the Patriots will look to grab their quarterback of the future and a tight end in the first three rounds of the draft. They need young blood at those positions.

But the first priority has to be an offensive tackle. They can’t leave Brady exposed on his back side.

Mike Lowe can be contacted at 791-6422 or:

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