TAMPA, Fla. -- A breakdown of the initial wave of free agency for the Tampa Bay Buccaneers:

Overall grade: B-plus. The Bucs locked up their own in re-signing wide receiver Mike Evans and tight end Cameron Brate to long-term extensions. They also brought back a key piece of their secondary in cornerback Brent Grimes. They then overhauled their defensive line by signing four new defensive linemen in Jason Pierre-Paul, Vinny Curry, Beau Allen and Mitch Unrein. They also made a big step in solving their rushing woes by signing center Ryan Jensen, allowing Ali Marpet to move back to guard. And while they did bring back Grimes on a one-year deal, and they re-signed safety Keith Tandy to a two-year deal, they still have needs at both positions, along with running back.

Most significant signing: Locking up Evans and Brate was a vital step in helping Jameis Winston going into Year 4 and beyond. Evans and Brate accounted for nearly 41 percent of the Bucs' receiving yards, 56 percent of their receiving touchdowns and 46 percent of their red zone targets over the past two seasons. As far as outside additions, while the Bucs gave up a lot in trading a third-round draft pick and swapping fourth-rounders with the New York Giants for Pierre-Paul, it was a move they absolutely had to make, not just because of Pierre-Paul's production (he has 58 career sacks) and the Bucs' lack thereof (only 22 total sacks last year, with only 8.5 of them coming from their defensive ends), but his durability. Pierre-Paul logged 964 defensive snaps in 2017, more than any other defensive lineman in the league. Over the past two seasons, the Bucs' trio of defensive ends -- Robert Ayers, William Gholston and Noah Spence -- missed a combined 22 games because of injury.

Most significant loss: Defensive tackle Clinton McDonald signed a two-year, $7 million deal with the Denver Broncos. From 2014 to 2016, McDonald started 31 games for the Bucs, but in 2017, he moved to a rotational role behind Chris Baker. He finished with five sacks in 2017, second most on the team. Aside from production, McDonald was one of the most respected voices in the Bucs' locker room and in the community.

Player they should have signed: The Cleveland Browns signed cornerback E.J. Gaines to a one-year deal worth $4 million. At 26, Gaines has three years in the league but still has room to grow with a team, which would have been the perfect situation for the Bucs, who might just have Grimes for one more year, depending on if he calls it a career after 2018. Gaines could have provided some experience to pair with Vernon Hargreaves after 2018. They're happy with Hargreaves at nickel but ideally, he would move to the outside.

Additions: Ryan Jensen, center; Beau Allen, defensive tackle; Mitch Unrein, defensive tackle; Vinny Curry, defensive end; Chandler Catanzaro, kicker; linebacker Cameron Lynch (was with the Bucs in training camp).

Subtractions: Clinton McDonald, defensive tackle; Kevin Pamphile, offensive guard/tackle; Doug Martin, running back (released); Chris Baker, defensive tackle (released); Robert Ayers, defensive end (released).

What's next: According to ESPN Roster Management, the Bucs have approximately $15 million in salary cap space, enough to re-sign cornerback Robert McClain, who is still weighing his options after a visit with the Arizona Cardinals, or another similar caliber player who could provide depth on the outside or at nickel. If anything, they'll bolster their roster with some depth players on short-term deals and look to the draft.