The Jacksonville Jaguars have put together arguably the league's best defense behind their plethora of young and proven talent. However, there have been some recent health concerns rising with one of their core pieces in rising star defensive end Dante Fowler Jr.

This has all risen from what is believed to be an upper-body injury that has forced him to miss time in the offseason workouts while impacting the physical shape that he's in. According to Hays Carlyon of 1010XL, Fowler Jr. is still dealing with the ailment that led to him losing some muscle mass in that area of his body.

That’s why a red flag went up in my mind when I saw him during the mandatory minicamp on June 13. Fowler missed the offseason program recovering from an upper-body injury. The Jaguars haven’t disclosed the injury (they don’t have to yet), but it’s obvious Fowler has lost sizable muscle mass in his upper body.

There isn't exactly a strong level of concern, but the fact that head coach Doug Marrone hasn't elaborated on the injury while voicing uncertainty about his status for training camp next month is something to keep an eye on. Fowler Jr. is coming off his most productive campaign where he posted a career-high 8.0 sacks, which created much optimism about his possibly building on that this upcoming season.

Jacksonville may have declined the fifth-year option on his rookie deal likely due to his continued issues off the field, the team is still high on him proving he can be a long-term piece of the puzzle. Fowler Jr. still has plenty of growth in his game to become a more complete and effective pass rusher, but the ability has certainly shown to be there.

These next few weeks prior to the start of training camp will be indicative of how serious the injury that he's dealing with at the moment. In the meantime, it's something that the Jaguars should continue to monitor closely.