You’ve heard from two headliners of the prospective marquee free-agent class of 2019, and you’ve heard that Erik Karlsson and Drew Doughty intend to reap rewards commensurate with their considerable worth. But you haven’t heard that kind of declaration from the star-spangled member of the class, which projects to also include Oliver Ekman-Larsson. And you won’t. Because that never has been Ryan McDonagh’s style. “You know what? I feel like I’ve got a great situation here, I love it both on and off the ice, and there’s no point at all in speculating about what might be down the road,” the captain of the Rangers told The Post last week. “Who knows what the situation is going to be? “A lot of it is going to have to do with how we play and how I play. The only thing I can control is how I play, so I’m not about to get into whatever different scenarios might come up. It’s not something that’s on my mind.” It’s going to be interesting. If McDonagh gets to free agency at what will be age 30, will clubs pounce on him as a cheaper (everything is relative) alternative to Karlsson, Doughty and, most likely, Ekman-Larsson? Or will they first establish the market, with McDonagh then left as an option for the teams that swung and missed on The Big Three? (Speaking of the Big Three: Under present-day conditions, how long do you think the Canadiens would have been able to keep the genuine Big Three of Larry Robinson, Serge Savard and Guy Lapointe intact following entry-level? Figuring, what, $11 million per for Robinson, $9 million per for Savard and $8 million per for Lapointe, probably not even for so much as a year. Which means that Montreal wouldn’t have traded Rod Langway at the age of 24. Isn’t the stuff of retroactive fantasy grand?)