VIERA , Fla. — Daniel Murphy is all in — Nat-urally.

“This red feels pretty good, I like that part of it,’’ Murphy said Sunday when asked what’s it like to be on the other side of the Mets-Nationals rivalry.

Murphy arrived in the Nationals clubhouse early in the morning and brought along his winning philosophy.

“It will be different, but it will definitely be very exciting,’’ Murphy said of the Mets-Nats battle in the NL East. “I think experiencing this rivalry over the last couple of years, it’s gotten very exciting and heated at times and I think that’s what makes for a good rivalry.’’

Turn up the heat another notch.

What about facing the Mets’ Young Guns?

“It’s a good, young talented staff, there is no doubt about that,’’ Murphy said. “I actually think I will be able to learn as much from the guys in this room who have faced them. Hopefully we can take what I saw on the field and maybe what they saw and see if we can put together the best approach to try to win ballgames.

“There’s a lot of [hitting knowledge] in this room, so I am going to keep my ears open.’’

He won’t have to go far. NL MVP Bryce Harper is right next door to Murphy. Harper was not in camp Sunday and will talk to the media Monday.

The home team has changed for Murphy, the ride down from Jacksonville is about an hour shorter, but it is still the same game and Murphy’s bat is the reason the Nationals signed him to that three-year, $37.5 million deal.

The Mets spent $75 million on Yoenis Cespedes, but they decided to let Murphy walk to their biggest rival.

On the same day Cespedes showed up in Port St. Lucie, saying he was “home,’’ Murphy showed up at his new home — the Nationals’ first full-squad workout isn’t until Thursday.

Murphy’s first words to his new teammates set the tone: Let’s get it on.

Indeed, let’s get it on — with the Mets and the rest of the NL East.

“It’s baseball season,’’ Murphy said about the excitement of the day.

“We’ve been waiting for this for four months. I got a really nice welcome from everybody here. I’ve been competing against these guys for so long, there are a lot of familiar faces in here. Now it’s just a matter of going to work.’’

The second baseman said he has had lots of interaction with the Nationals over his career simply because, “a lot of them get on base a lot.’’

Dusty Baker told The Post Saturday that when he first spoke to his new player, Murphy said he would do whatever the manager wanted.

Murphy, 30, said all he cares about is one thing.

“This is about winning baseball games,’’ Murphy said. “How can we do that as a group, collectively. I’m going to do whatever I’m told. I’ve always felt that if you get to the end of the season and you have accomplished all the goals you have set as a team, than individually, it’s going to look the way you want it [to look].

“Whatever Dusty wants to do as far as positioning, batting order, that’s fine, we get the fun part, just go play.’’

What are his goals?

“To win,’’ Murphy said flatly.

Murphy, a lifetime .288 hitter, is the hitting reason the Mets beat the Dodgers in the NLDS and swept the Cubs in the NLCS when he was on fire, blasting seven postseason home runs.

Baker has not decided where to hit Murphy but did say he would want to break up the two lefty hitters, Murphy and Harper.

Looking back on his seven-year Mets career, Murphy said: “I’ve built some really, really steady relationships that I think will go beyond baseball. What more can you ask for out of this game than the relationships that my wife and I have been able to build and we are excited about the ones we are going to build here as well.’’

Murphy said he texted David Wright.

“I just asked how he’s doing, how he’s feeling. I know he is taking it slow down there,’’ Murphy said. “He’s starting to understand that it is a long season and he wants to get healthy for the whole thing.’’

A long season, a strong rivalry. Let’s get it on.