JACKSONVILLE – Senior writer John Oehser's five key storylines to watch in Jaguars 2015 organized team activities, which begin Tuesday at the Florida Blue Health and Wellness Practice Fields …

1. Quarterback. Most of these storylines involve position battles. Such is the competitive nature of the Jaguars' roster entering OTAs with the offseason addition of draft choices and free agents at many positions. There's no battle at quarterback, but because of the need for second-year veteran Blake Bortles to develop it's still the No. 1 position to watch. How improved are his fundamentals after two months of offseason focus on the area? How has his chemistry improved with young receivers such as Marqise Lee, Allen Hurns and Allen Robinson? How will the addition of tight end Julius Thomas help the passing game? All are storylines to watch for Bortles, but then, pretty much anything Bortles does in the coming weeks and months will be a storyline to watch.

2. Left guard.We'll begin this section by clarifying that it's difficult to tell too much about the interior of the offensive line until the Jaguars start working in pads in August. But the interior of the line is a critical offseason storyline and became more intriguing when the Jaguars selected A.J. Cann in Round 3 of the 2015 NFL Draft. Zane Beadles, signed as unrestricted free agent in the 2014 offseason, enters OTAs as the starter and likely will remain there until at least training camp. But look for Cann to work extensively at left guard and he's expected to push Beadles sooner rather than later. Another key position on the interior is center, but Stefen Wisniewski – who signed as an unrestricted free agent from Oakland in the offseason – isn't expected to be ready to practice until training camp. That's when the expected battle with Wisniewski and second-year veteran Luke Bowanko – as well as the overarching storyline of the development of the entire offensive line – likely will get interesting.

3. Free safety.This position may not be wide open, but is there competition? Almost certainly. This is a position the Jaguars tried to upgrade by pursuing Devin McCourty from the New England Patriots early in free agency this offseason before signing Sergio Brown as an unrestricted free agent from the Indianapolis Colts shortly thereafter. Brown is the starter entering OTAs, but the Jaguars drafted James Sample from Louisville in the fourth round of the 2015 NFL Draft. Sample played mostly strong safety in college, but the Jaguars believe he has the skill set to play free safety. The Jaguars spent a significant amount of offseason effort on this position, and how it will look in the fall probably will play out in OTAs and training camp.

4. Running back.That these five storylines have a heavy offensive slant is understandable; not only are OTAs skill-position oriented workouts, there are intriguing storylines everywhere around Bortles this offseason. That's true at running back, where rookie second-round selection T.J. Yeldon almost certainly will start but where little else is certain entering OTAs. Denard Robinson, a nine-game starter last season, could have more of a reserve/weapon/kick returner role, and last season's Week 1 starter – Toby Gerhart – also could have a reserve role with some short-yardage and third-down emphasis. Second-year veteran Storm Johnson and Bernard Pierce – acquired off waivers from the Baltimore Ravens in March – also will be competing for time at what suddenly is a deep position. The Jaguars won't carry a fullback this season, which could open an extra roster spot for a running back.

5. Tight end.There's no position battle here, but there may be no more interesting position to watch in Jaguars 2015 OTAs. The team signed tight end Julius Thomas as an unrestricted free agent in March from the Denver Broncos, and he immediately became the most-accomplished player on the Jaguars' offense. He caught 24 touchdown passes over the last two seasons and the expectation is he will help not only the tight end position, but the passing game as a whole. The team also retained veteran Marcedes Lewis at the position, and while he will take on a new role, he remains a solid blocker and an elite-level talent. The presence of both Lewis and Thomas could give the Jaguars one of the deepest, most-talented tight end groups in the NFL. How will new offensive coordinator Greg Olson use that combination? The details of that answer may not be known until training camp, but OTAs could provide the first indication.