JACKSONVILLE – The fans made their offseason debut and a rookie did, too.

Those were among the themes of Tuesday's first practice of Jaguars 2016 mandatory minicamp, a late-morning practice that Head Coach Gus Bradley said in addition to being really, really hot had something of a back-and-forth feel.

Bradley said that wasn't a bad thing, with both the offense and defense having productive sessions during the first mandatory practice of the offseason.

"It was good," Bradley said following a two-hour workout at the team's practice facility adjacent to EverBank Field. "I thought that the defense struggled in the 7-on-7 [work]. Offense went to a third-down period and then the defense went really well. There again it went back and forth.

"There was a period when we were in red zone and it went back and forth. That's what you are going to see a little bit of."

An announced 2,377 fans attended the open practice, with a second free-and-open-to-the-public session scheduled for Wednesday at 9:35 a.m.

Rookie linebacker Myles Jack, a second-round selection in the 2016 NFL Draft, made his Jaguars debut. He had yet to practice in the offseason because of a rule not allowing rookies to work in offseason programs until their schools finish their final classes of the school year.

Rookie Jalen Ramsey, the No. 5 overall selection in the 2016 NFL Draft, continued to sit out the offseason after undergoing surgery to repair a small meniscus tear late last month.

Also not participating Tuesday was Pro Bowl wide receiver Allen Robinson, whose absence from offseason practices has been mostly precautionary.

"He's doing really well," Bradley said of Robinson. "We are being more cautious than anything with him. I saw him sprinting over there [on an adjacent field] and we'll evaluate it again tonight."

Fans attending practice Tuesday saw quarterback Blake Bortles pass effectively at times, completing long passes to wide receiver Marqise Lee and wide receiver Rashad Greene. He also completed a long pass down the right sideline to tight end Julius Thomas late in practice that may have been the most memorable play of the day.

The defense finished the day with two interceptions, including one by free safety Peyton Thompson – who was working with the second-team defense – and one by safety Jarrod Wilson. There were several long runs by the running backs early in practice, and tight end Marcedes Lewis had several long receptions down the middle of the field.

Defensive tackle Malik Jackson had a pass deflection at the line of scrimmage, but overall line play – as well as much of the rest of practice – was difficult to evaluate because of the non-padded nature of the work. The Jaguars' final two days of minicamp practices – like the rest of the offseason – will remain non-contact and non-padded.

The Jaguars will begin practicing in pads during training camp in July.

"I think when you put the pads on it will tell a true story," Bradley said. "Right now guys are letting up on the end to stay away from the quarterback and staying away from putting on hits, so we'll get a better feel during training camp."

Also on Tuesday:

*Jaguars linebackers coach Robert Saleh discussed the offseason of linebacker Dan Skuta, who missed practice Tuesday while continuing treatment on a sports hernia sustained last season. Skuta, who had practiced throughout organized team activities, has been working at the Otto position where he started last season. He also is expected to work as a pass rusher in some passing situations. "Skuta looks much more comfortable this year," Saleh said. "He has a lot of hope for this year also and deservedly so. He wants to rush the passer, he wants to be involved more and all that stuff along with playing the Otto position where he's a buzz dropper and playing man coverage. He looks good. He looks comfortable doing it and it looks like he's in a really good place mentally." …

*With Skuta not practicing, Ryan Davis worked with the starters at Otto Tuesday. He is working at Otto after playing the Leo the past three seasons. "He's got a better appreciation for linebacker play now that he's gone from D-line to linebacker," Saleh said. "Now it's just a matter of putting all that God-given ability and all that athleticism he has and allow his mind to catch up. Once his mind catches up it's going to look really good." …

*Among other players not working in team drills Tuesday: right tackle Jermey Parnell (hand), cornerback Rashaad Reynolds (groin), left tackle Kelvin Beachum (knee), offensive lineman Luke Bowanko (hip) and defensive tackle Sen'Derrick Marks (triceps). …