NHL

Rangers’ Frolov done for season with knee injury

The inclination might be to minimize the significance of the season-ending right-knee injury Alexander Frolov sustained in the Rangers’ 2-1 victory in St. Louis on Saturday — for the fact is, the winger, who has been a disappointment through the first half of the season, was back on the fourth line when he went down for the count.

But there’s more to it. For not only are the Blueshirts already soldiering on without previously injured forwards Ryan Callahan and Erik Christensen (and Derek Boogaard and Vinny Prospal), coach John Tortorella trusted Frolov in any situation, which is something that cannot be said as it relates to all the forwards on the roster.

For better or worse, Frolov was a recent staple on the second power-play unit. What’s more, Tortorella believed in Frolov’s ability to protect the puck and play away from the puck; hence, if there was a choice to be made for a winger to get ice time in a defensive situation or late in a tight game, the coach as often as not chose Frolov.

Now Frolov is out of the equation after suffering extensive damage to his ACL, MCL and meniscus that will require surgery.

The injury occurred when the Blues’ Brad Winchester fell on Frolov’s right leg late in Saturday’s third period. The 28-year-old winger who signed a one-year, $3M deal as a free agent out of L.A. thus finishes the year (and all but certainly his Ranger career) with only 16 points (7-9) in 42 games.

The Rangers likely will hunt for a veteran replacement who can fill Frolov’s 14:25 per, but they won’t overpay, what with Callahan, who was given the green light to begin skating yesterday, due back in another three weeks or so from the broken hand he sustained on Dec. 15.

For the short term, at least, we’ll see whether the coach will choose to give Chris Drury, who has been buried in a fourth line and penalty-killing role since Christensen went down with a knee on Dec. 29, the opportunity to get some offensive minutes on that second power-play unit.

And we’ll find out whether Sean Avery, impressive in the three games since he replaced Frolov at left wing on the line with Artem Anisimov and Marian Gaborik, and who barreled to the net to slam home the winner against the Blues, can cement his role as a top-nine forward on this overachieving team that will go into tomorrow night’s match at the Garden against Montreal with a rather astounding 25-15-3 record.

Veteran journeyman Kris Newbury will serve as Frolov’s replacement on the roster, at least for the moment, following his recall yesterday afternoon from Connecticut. The 28-year-old forward, whose natural position is center, has 35 points (5-30) in 41 games for the AHL Whale.

Christensen is believed a month to six weeks away from the rejoining the lineup. There is no ETA on Prospal, who resumed skating yesterday after taking eight days off due to swelling in his surgically repaired knee.

Regardless, it would be folly to count on much, if anything, from Prospal even if he can make it back after being sidelined the entire year. Any contribution would have to be considered a bonus.

larry.brooks@nypost.com