The Bucs were active in free agency and busy in the draft, and while they're not necessarily done adding talent to their 2018 roster, they're at that point where you can anticipate the biggest position battles looming ahead in training camp and the preseason.

We'll get to battles for roster spots later, but for now, here are five starting jobs that seem to be very much up for grabs, sometimes with more than two players vying for a spot. Especially when rookies are involved, that competition can carry well into the regular season as well.

1. RUNNING BACK: Third-year pro Peyton Barber, barely used until the final month of last season, finished strong enough to lead the Bucs in rushing. Tampa Bay didn't add any new backs in free agency, but used the first of its three second-round picks on USC's Ronald Jones, who brings big-play potential to the running game.

Barber and Jones will likely share the load at the start of the season — the battle will be how quickly Jones can earn the confidence and trust of Bucs coaches in key skills like pass protection. The rookie is competing with three returning backs (Barber, Jacquizz Rodgers, Charles Sims) who have at least two years in Dirk Koetter's offense, so he'll need to learn his playbook quickly to build on his role going into the season.

2. RIGHT GUARD: With newcomer Ryan Jensen at center, shifting Ali Marpet to left guard, the only real uncertainty on the offensive line is right guard, where J.R. Sweezy is still sidelined by a knee injury, his future very uncertain.

GM Jason Licht spoke last week of "tough decisions" ahead in the context of Sweezy — due to make $6.5 million in 2018 — getting back healthy. Cutting him would speak highly of the Bucs' confidence in two young players: third-year pro Caleb Benenoch, who started five games at tackle last year, and third-round rookie Alex Cappa of Division II Humboldt State.

The Bucs aren't expecting Cappa to make the same small-school-to-NFL leap that Marpet made three years ago, starting from Day 1. Dirk Koetter called Benenoch "the wild card" in March, and he'll have a small window to establish himself as a starter before the rookie gets his bearings.

3. DEFENSIVE TACKLE: The easy answer is that the Bucs are going to rotate all across the upgraded defensive line, getting seven or even eight guys regular snaps in the team's most improved position.

Again, it's veteran vs. rookie — the Bucs are very high on Beau Allen, signed from the Eagles as a priority in free agency, but they also put their first-round pick into massive 347-pound prospect Vita Vea. First-round picks are expected to be starters, so it's more a matter of finding the best way to make optimal use of both (as well as newcomer Mitch Unrein) as complements to Gerald McCoy on the Bucs' interior.

Is Vea quick enough to play on third downs? Will the new DT depth allow the Bucs to rest McCoy a little more reasonably than in past seasons? This will be an ongoing equation throughout the season with five newcomers meshing across the defensive line in a crucial area for Tampa Bay.

4. CORNERBACK: The Bucs didn't sign any newcomers in free agency, bringing 35-year-old Brent Grimes back for another season to secure one starting job. Even with an upgraded defensive line to give opposing quarterbacks less time to throw, third-year pro Ryan Smith will find a strong push on the opposite side from second-round rookie Carlton Davis, if not fellow second-rounder M.J. Stewart as well.

Stewart is more likely to challenge Vernon Hargreaves inside at slot corner, but there are four months to shake out the strengths and best spots for both rookie corners. Tampa Bay specifically hasn't re-signed veteran Robert McClain, who provided depth inside and outside, so they've made it clear the rookies will find their way onto the field in some fashion.

5. SAFETY: The Bucs didn't add anyone in free agency, but exercised Chris Conte's option and re-signed Keith Tandy for familiar options, knowing second-year safety Justin Evans has one starting job locked up.

Fourth-rounder Jordan Whitehead from Pittsburgh is a safe bet to make the roster, and like Evans a year ago, his role could steadily rise as he gets more experience and familiarity in the Bucs defense.

If Whitehead hasn't impressed in training camp, this is a position where the Bucs could make a late addition, like they did a year ago in former Pro Bowler T.J. Ward, who wasn't re-signed. But if Whitehead picks up the defense, he'll challenge Tandy for the third safety job, if not Conte for a starting role opposite Evans.