They play two entirely different sports with two vastly different body types.

Brandon Spikes is a 6-foot-2 beast of an inside linebacker who weighs 255 pounds and flies around the football field trying to punish whoever gets in his way. He sees the target and destroys it.

Rajon Rondo is a 188-pound, 6-foot-1 point guard who directs one of the best basketball teams in the world. Rondo sees the target and flies right by it, doing his damage many times without the opponent even seeing him on the radar.

Both have disarming and genuine smiles, with incredibly unique senses of humor away from the field and the court.

Both are intimidating presences on it.

I had the chance to speak to and interact with both on Thursday, as the Patriots prepared for their bye and the Celtics put Tuesday night in Miami behind them with a two-hour practice all about communication and execution.

And something immediately came to mind. Spikes and Rondo might not share the same physique, but they share the same M.O. – don’t mess with them on the field or on the court or you’ll pay the price.

Let us not forget, Spikes and Rondo have had their run-ins with management that led directly to speculation that they were not long for Boston.

It was Spikes who was reprimanded for an alleged sex tape just months after the Patriots drafted him. It was Spikes who tweeted his rage at replacement officials in the hours after the loss in Baltimore this season.

With Rondo, most of his issues have had to do with the way he handles himself with authority, namely NBA officials and -- early in his Celtics days -- coach Doc Rivers. Lately, he’s kept it confined to Ray Allen and Dwyane Wade.

Both Spikes and Rondo crafted their killer instinct in vastly different ways.

Spikes learned his in the heat of battle through violent contact on the football field. His inspiration? None other than one of the original nasty characters in NFL history: Bears middle linebacker Dick Butkus.

“His approach, his demeanor on the field, his passion,” Spikes said Thursday. “He just imposes his will on guys. You can tell he just loves the game.”

What did he learn watching film of Butkus?

“Honestly, there’s no greater feeling than when you can impose your will on another man and absolutely stop what he’s trying to get done,” Spikes said. “It’s kind of fun. I get a kick out of it.”

Both Spikes and Rondo have a “me against the world” mentality, as Spikes -- who has gotten into numerous spats on Twitter -- likes to remind his followers. On Thursday, as he was chatting up reporters, he was wearing a bright red had with yellow letters and a heart symbol. “I [heart] haters” was all it read.

He knows his style can be abrasive and offensive. There was no greater example of that than his tweet jokingly comparing a fear of spiders with homosexuals. He screamed at his “haters” on Twitter to just “chill.”

He told us Thursday that while people might think he’s a beast on the field, he’s anything but off of it.

“Maybe it’s just a competition thing. I’m cool, calm, and down to earth,” Spikes insisted. “Anybody can come up to me. Half of the people will probably be scared, but when they do [meet me] they think, ‘He’s nothing like I thought he’d be.’ I think it’s just the competitiveness in me. I just want to get an edge on guys. I feel like if I can get any advantage on them, I can beat them every day.”

Back to Butkus. One reason the former Bears legend is a role model for him is how he played the game.

“I’ve see it on TV, some of the history in the game,” Spikes said. “He’s just a guy that stuck out to me. He was always just killing guys, making plays. He was always in the middle of the defense. He was one reason why I played the position. I’m just trying to mold my game after him and his killer instinct.”

What about getting those NFL fines now that didn’t exist when Butkus played?

“Don’t worry about it,” Spikes said. “He just told me to keep hitting people.”

Rondo is far subtler -- most of the time. Rondo was asked what the focus of practice was on Thursday. He looked at the reporter. He looked away. Then, with a wry smirk on his face, he said “defense.”

That’s the way Rondo is.

He can stare you down. He can laugh at your question. But he also can provide insight to the brilliant basketball mind that is running the Celtics now. He is behind the wheel of a Ferrari -- and, like his fake behind-the-back pass, he wants you to know he’s quite comfortable driving it.

As we learned in the last 12 months, he can say things that get under the skin of teammates and opponents alike.

But when he’s on the court, there’s no one Paul Pierce and Kevin Garnett listen to more.

He runs the show. He’s the boss. Pierce is the captain, and KG is the heart and soul of the Celtics. Yet, when Rondo directs, they don’t question.

That has resulted in Rondo ascending to the role of field general of the Celtics, a team that has won five straight Atlantic Division titles, one NBA title and another Eastern Conference championship and has advanced to the Eastern finals one other time.

But as we saw again on Tuesday night, there’s a badass side to Rondo that you don’t mess with.

Late in the fourth quarter, Dwyane Wade drove to the basket and Rondo stuck out his left arm and applied the clothesline.

Rondo had had it with Wade and the Heat on that night. Rondo thought Wade got away with an obvious hook on a drive to the basket with 7:14 left in the fourth. Before he could even get his mouthpiece out to argue, Rondo was hit with a technical for charging toward the official.

“That’s how it is,” Rondo said Thursday. “On that particular play, I asked him what was the reason and I still had my mouthpiece in so the words didn’t come out of my mouth correctly, at first anyway. But I got the tech and that’s what it is.

“No, I didn’t curse at [the official]. If you see the film, I just told him that I thought he hooked me. I was walking towards him and that’s where the “respect of the game” rules come into to play, and I was popped with a tech.”

Was Rondo trying to make a statement when, with 16.9 seconds left and the Heat comfortably ahead, he clotheslined Wade?

“I don’t think it was a hard foul,” Rondo said. “He sold it a little bit and that’s basketball. They were up and he drove to hole and I didn’t want to give up a layup. Simple as that. I didn’t yank him down or [commit] a dirty play like you’ve seen with him in the past. That’s what it is.”

Funny, when Rondo was asked point blank if he thought he was a menacing factor on the floor, he rejected the suggestion immediately.

“No. No way,” Rondo said.

But, truth be told, that’s part of Rondo’s character. He is a menace on the floor. Menace is defined as: a person likely to cause harm; a threat or danger.

That’s perfectly sums up Rondo and Spikes. They may have different styles, but both are a danger anytime they suit up. They can go off at anytime and they are both game-changers.

But, as is the case with any highly charged weapon, the key is making sure they don’t self-destruct at the wrong time.