EAGAN, Minn. — T.J. Hockenson is nearly four months into his return from a torn ACL suffered against Detroit on Dec. 24.

He's advanced from bedrest in the early days to integrating himself back in the weight room — "squattin,'" he said, almost with a touch of Nashville drawl he absorbed from his offseason home — Monday when Vikings players reported to Twin Cities Orthopedics Performance Center to open the team's voluntary offseason workout program.

"It's day by day, it's week by week, and obviously negative thoughts creep in all the time," Hockenson said of the long recovery. "That's just human nature. But, you know, in order for you to come out of things like this, you've got to go through the dark times and be able to come back and see the light, and that's kind of what I've done.

"I mean those first few days, few weeks where you can't do anything, you're just on bedrest, that's a dark time, you know, and so now to be able to get back and start doing some rehab and start to squat and start to really integrate myself into doing some football stuff is you start to see the light and you start to realize, 'Hey, this is temporary, and we'll be back from this.' But you learn a lot about yourself and you learn a lot about who you are," he added. "And the dark times make the bright times better."

That's a truth that could accompany three chords on Music Row.

Hockenson is appreciative and pleased with his progress so far. The first good news occurred when his MCL healed and did not require surgery in addition to the repair of the ACL. His physician told him the operation went "fantastic" and is "very straightforward."

Hockenson then shifted to rehab efforts and was visited in Nashville by Vikings Vice President of Player Health and Performance Tyler Williams and Director of Rehabilitation/Assistant Athletic Trainer Matt Duhamel.

"We have a really good training staff here," Hockenson said. "They've done a really good job just with the plan so far and laying out blocks. …

"I really do give credit to Minnesota Vikings and the training staff and the people upstairs for, you know, setting me out to be the best that I can be in these blocks and really coming up with a plan to make sure that whatever the timeline is at the end, just to make sure that these few weeks and these blocks are attacked and set a standard that will get me back to the best I've been playing," he added.

Brian O'Neill, who successfully rehabbed a torn Achilles last offseason, also spoke Monday. Asked about the lessons he learned during that process that he's passed along to Hockenson, O'Neill said, "Not every day is going to be a step forward. There's going to be some, ride the wave, ride the peaks and valleys a little bit. But just stay true to your process and keep a positive mindset. And you have more time than you think."

"I remember coming back last spring and limping up on this stage [in the media interview room at TCO Performance Center] thinking, 'I don't know; it's going well, but we're a long way off,' " O'Neill added. "He's a true pro, so he'll do things the right way, and he'll be back for sure."

Vikings Head Coach Kevin O'Connell also expressed optimism with Hockenson's trajectory, which doesn't have a fixed timeline.

"I've been really excited about the way T.J. has attacked the process, really since a very successful surgery. He's [making] daily improvement, and that's all we're really hunting right now," O'Connell said. "He's been a very, very special player for us. We're going to be smart about it throughout the process, but having him here and having him around his teammates, he's one of our leaders."

Hockenson's had plenty of time to think about the hit that has placed him on this course.

He pulled in a pass at the Minnesota 39-yard line and turned up the field. Lions safety Kerby Joseph led with the crown of his helmet and made forcible contact with Hockenson's right leg at the knee as Hockenson reached the 42. He flipped forward and held onto the football. The gain of 24 on the play came with losing Hockenson for the rest of the season.

Hockenson was asked about the hit by his former Detroit teammate, who was involved in a low hit (in the NFC Wild Card Round three weeks later) during which Rams tight end Tyler Higbee tore his ACL and MCL.

"I wasn't too happy about it. That's not a fun one to take," Hockenson said. "And that's not necessarily based on him as a player. I got nothing against him. I played with him in Detroit."

Hockenson pointed out how rules now prohibit offensive players from making cut blocks on defenders outside the tackle box.

"When you're 25 yards downfield, looking back at the quarterback, you don't have any awareness, you know? And then to have that happen again, [three] weeks later, I didn't really like that," Hockenson said. "So that's probably the most extent I'll say on that. But I definitely don't think I have it against the player as much as the league putting the defense in those positions in order to have to do that."

Rules already make it a penalty for a defender to strike in the head and neck areas, and last month, NFL Owners voted to ban the hip drop tackle because of its potential to cause injury.

Hockenson hopes the NFL examines if more can be done to prevent the type of hit that sidelined him. He pointed out that having the helmet down "doesn't put the defensive player in a good position."

He said he approaches football with the mindset that everyone will compete as hard as possible but also take the field with a mutual understanding that injuring opponents should not be the intent.

"I don't think it was. I mean, like I said, I know Kerby pretty well. I've played with him," Hockenson said. "I don't necessarily think it was. You go back on the tape, and you see, obviously, what happened. But I know him. I don't think it was. I just want to make sure it wasn't, and I want to make sure that that's — and that's why I'm using my voice here, is to just, players protect players. And that's in any facet of the league.

"You don't want a defensive guy head hunting, or you don't want a defensive guy knee hunting, and the same thing for an offensive guy," he added. "You don't want me to come across the line and just try to come after you and take you out. That's not my goal. That's not anybody's goal. My goal is to get my job done and to help this team as much as we can. But there's also ways to do that without injuring a guy and without affecting his career in a certain sense."