TAMPA, Fla -- To those concerned that Tampa Bay Buccaneers wide receiver DeSean Jackson wasn't performing up to par in 2017 or that he's starting to decline at age 31 -- the coaching staff doesn't see it that way.

"DeSean Jackson is a really good football player. His track record shows that, and if you just had an ISO camera on DeSean Jackson when he was on the field this year, DeSean Jackson wins most of the time," said head coach Dirk Koetter. "When he is trying to get behind the defense, he can get behind the defense. We did not do a good job of getting him the ball in positions that he is used to getting it, which is over the top."

Jackson caught 50 passes for 668 yards, the second-lowest mark of his career, behind only his 2015 season where he played just nine games. His 13.4 yards-per-catch average was a career-low.

Jackson made his living the past 10 years on deep passes, where he can use his speed to fly downfield. The intent to get him those balls was there, however. Jackson led the league with 15.82 air yards per target. He had seven targets of 40 or more yards but did not catch a single one of those passes. In his three years with the Washington Redskins, he had 11 catches for 40-plus air yards and 30 for his career.

On passes of 30 or more air yards, he was targeted 11 times and mustered zero catches. Mike Evans, on the other hand, had one catch for 40 or more air yards (thrown by Winston) and five catches on passes of 30 or more. Evans had three three catches of 30-plus air yards last season, but deep passes don't impact his game the way they do Jackson's.

"I think DeSean did his part, Koetter said. "I see it out there in practice, I see it on the game tape. DeSean Jackson hasn't lost a step or anything like that. Whether it was by play design or whether it was Jameis' injury during the middle part of the season when maybe Jameis didn't have the confidence that he could put it on the money over 40 yards down the field, but we didn't do a good job in that area."

Winston suffered a sprained AC join in the right shoulder of his throwing arm. The team announced his injury after Week 6, but sources close to Winston say that it actually happened against the Minnesota Vikings in Week 3, meaning he was struggling through the injury for a lot longer that people realize. Winston was ultimately sidelined by it after Week 9 and didn't return until Week 13.

"After he came back from the injury, I think Jameis improved his deep-ball throwing," Koetter said. "He had two examples of that [against the New Orleans Saints] -- the one in the first half down the New Orleans sideline to Mike. That ball was right on the money, and then obviously the last throw of the game to Chris [Godwin]. You just can't help but think, 'Where was DeSean Jackson on those plays?'"

Winston believes it also boiled down to chemistry and likened it to his first season with Evans, when the two had to find their sweet spot. That meant spending a lot of extra time together in the offseason, and Winston is hoping to do the same with Jackson.

"Not many quarterbacks get an opportunity to play with a guy like that," Winston said of Jackson. "So having a guy like that, you've gotta work with him, and DeSean and I have talked about our offseason program. DeSean and I did work together in the offseason, but not as much as we want."

Jackson was not a participant in every OTA workout, but attendance isn't mandatory.

"With him coming to offseason workouts this year -- he's a veteran guy -- but we have to get our work in, man," Winston said. "A lot of that has to do with just me being able to get him the football in the way that he likes the football. That's gonna be important. So I'm gonna sit down and talk to him and go over some things with him."

Jackson was inactive for the final two games because of an ankle injury, and Evans' lone catch of 40-plus air yards came in Week 15 against the Atlanta Falcons.