TAMPA —The NFL draft still is a few weeks away, and every team is hoping to harvest players who can be the difference on a winner.But the biggest improvement may come from players entering their second or third seasons. Rookies are great, but player development is the secret sauce of any winning franchise.To that end, the focus on 2018 should eventually shift away from draft picks to those players poised to make the biggest improvement. For the Bucs, they are a former first-round pick, a versatile offensive lineman, a twice-injured pass rusher, an ascending receiver and determined quarterback.O.J. HOWARD: He was considered one of the most complete players in the draft, a tight end equally adept at blocking as he was catching passes.By nearly every measure, Howard had a good rookie year. He caught 26 passes for 432 yards and six touchdowns. But he could've become an even bigger red-zone target. (Remember the final play of the Patriots game?). He also can improve as a run blocker.But coach Dirk Koetter seems confident Howard has the type of makeup to improve rapidly."I know he had tapes he studied in the offseason," Koetter said. "I think O.J. is going to see his room for improvement is immense. He can do so many things better and he's capable of doing them. That's one thing we loved about O.J. He's a do-everything tight end."CALEB BENENOCH: The Bucs signed Ravens center Ryan Jensen and are moving center Ali Marpet to left guard. All that is left is to determine whether J.R. Sweezy, who could miss some time in the offseason recovering from a leg injury, can keep his job at right guard. The Bucs appear ready to move on to Benenoch, a fifth-round pick from UCLA.Benenoch's versatility has been his best attribute. He's been able to provide help at guard and tackle. But barring the Bucs using a high draft choice on a guard — such as Notre Dame's Quenton Nelson — Benenoch could benefit from focusing on one position."The one thing we feel like from watching Caleb's tape, if it would ever be possible for us to put Caleb in a spot and leave him there, it would probably help him just because Caleb is one of those guys that's been moved around so much, that he's never really gotten used to playing somewhere,'' Koetter said."One week he's playing left guard and the next week, he's at right tackle. I think there's a little bit of an art to that. We have high hopes for Caleb, and don't forget, we still have the draft. We have a long road to go here before we have to solve this for real.''NOAH SPENCE: A year ago, Spence was the Bucs' big hope on defense. The lack of a productive edge rusher was already evident before he suffered a second shoulder injury. He played in only three games and underwent another surgery.The good news for Spence is that he's had a good, long period of recovery. But the Bucs traded for two defensive ends, Vinny Curry and Jason Pierre-Paul. Those acquisitions will enable Spence to focus on what he's likely to become — a designated pass rusher. At 6-2, 251 pounds, he always will have trouble holding up physically as an every down player."I know Noah is ahead of schedule. He looks great," Koetter said. "Does it take the pressure off him? I don't know if it takes the pressure off him, but it allows us to play him in a pass rushing role and not so much on every down.''CHRIS GODWIN: Godwin battled through a series of injuries and played predominately on special teams. When DeSean Jackson missed the final two games of the season with a foot injury, Godwin responded with 10 catches for 209 yards, including a game-winning touchdown against the Saints.It appears the Bucs still are committed to improving their use of Jackson, but Godwin could force his way on the field more."He'll do what you ask him to do and he'll do it to the best of his ability and he'll play through discomfort," Koetter said.RYAN GRIFFIN: Who knows what becomes of the NFL's investigation of possible misconduct by Jameis Winston? The Bucs felt it was important to re-sign Ryan Fitzpatrick, who went 2-1 as a starter when Winston was injured.The Bucs also like Griffin, who was winning the No. 2 quarterback job a year ago in training camp when he suffered a shoulder sprain. Griffin is in a tough spot. He's gotten better each year, and after three seasons with the Bucs is still waiting for his first regular season snap. If he can stay healthy and continue to improve, he could gain some ground on Fitzpatrick.