When NFL free agency officially starts at 4 p.m. Wednesday, the New England Patriots will have a short list of offensive needs. That’s no different from any other year. What makes 2018 different is that the team’s success in the open market will likely hinge on which of its own players the team can retain.

The Patriots enter this week with around $22 million in cap space. Monday marked the start of the NFL’s “legal tampering period” where teams can discuss deals with perspective free agents. It’s in this 48-hour window where the Patriots will have to make some headway with their offseason priority – retaining Nate Solder.

Solder headlines a small group of Patriots free agents. It just so happens that the 29-year-old also represents the best left tackle available in free agency. Starting 95 of 98 games over the last seven seasons, Solder has one of the most important jobs in Foxborough – protecting Tom Brady’s blindside.

A Pro Bowl alternate last year, Solder’s market is said to be rising. In the event another team offers Solder around $13 million a year, the question then becomes, “Can the Patriots come close?” The nightmare scenario is that the Patriots lose their starting left tackle to start the offseason since there’s no clear-cut replacement.

It just so happens that their two backup tackles, LaAdrian Waddle and Cameron Fleming, are free agents. Both also played right tackle last year. Another option, last year’s third-round pick Tony Garcia, lost 40 pounds last year after it was discovered that he had blood clots in his lungs. In free agency, there’s no clear-cut replacement, either.

Justin Pugh is an option, but he’s played left guard and right tackle. He’s also coming off a back injury. Someone like Chris Hubbard is young at 26, but his experience in the NFL is also at right tackle in Pittsburgh. The truth is, if Solder leaves, the best bet may be to just bring back Fleming and/or Waddle to fill the role until a more permanent solution comes along.

On offense, Danny Amendola, Dion Lewis and Rex Burkhead also represent the Patriots’ free agents.

Amendola’s in an interesting situation. At 32, he’s running out of time in the NFL so this could be one of his last chances to cash in. There’s no denying his connection with Brady or his perfect fit in the Patriots’ offense. Losing the slot receiver would certainly hurt, even with Julian Edelman set to return. After Solder, Amendola should be another priority for the Patriots.

Sure, they have bodies at receiver – Edelman, Brandin Cooks, Chris Hogan, Malcolm Mitchell, Kenny Britt, Phillip Dorsett, etc. – but they don’t have a pure slot receiver.

With the cap situation being what it is, it remains to be seen if the Patriots would even attempt to replace Amendola with a potential free agent. Options would include players like Marqise Lee, Bruce Ellington, Taylor Gabriel or someone like Albert Wilson.

At running back, the Patriots are in another tough spot. Although the door isn’t shut completely, it’s not expected that Lewis will return.

He’ll likely earn more on the open market and that could also be the case with Burkhead, whose market is also expected to be strong. In the event the Patriots lose both backs, they’ll be left with James White and Mike Gillislee.

The Patriots might be best served to replace Lewis and/or Burkhead in the draft, but there are free agent options available.

Doug Martin is intriguing and he also has a history with Bill Belichick’s friend, Greg Schiano. Another option, Jerick McKinnon has skills that are similar to Lewis and Burkhead. If the Pats are looking for a back who can catch and run, Damien Williams could be a possibility. The Patriots brought him in for a free agent visit last offseason. A restricted free agent, Corey Grant is intriguing. He surprised the Patriots in the AFC Championship game with three catches for 59 yards.

Another big storyline for the Patriots is at tight end. If Rob Gronkowski decides to play, the Patriots likely won’t make a big splash in free agency. In the event he retires, all bets are off. The fact that he’s even considering hanging up his cleats should give the Pats reason for pause.

If Gronk leaves, the Patriots might be forced to look at someone like Jimmy Graham. Other tight end options include Trey Burton, Tyler Eifert and Austin Seferian-Jenkins.

For the Patriots, the potential of losing Soldier is scary enough. Add Gronk to the list and this next month could become frightening.