That Pekka Rinne is one of the few elite goaltenders in the National Hockey League is uncontroversial.
But that’s only half of the reason why his injury is such a serious hurdle for the Nashville Predators—a team likely to be in a life-or-death battle for a spot in the playoffs this season.
The other reason is that the two goalies Nashville has as alternative options have a combined six games of NHL experience. Backup Carter Hutton played one game for Chicago last season and has five under his belt with Nashville this season, while third-stringer Magnus Hellberg’s only NHL action came in relief of Hutton against St. Louis last Saturday.
How much of a drop-off is it from Rinne to Hutton/Hellberg and is that drop-off going to kill Nashville’s playoff hopes?
The first matter at hand is the extent of Rinne’s injury. The Predators have announced that he will be out for a minimum of four weeks, which is serious but represents a relatively small portion of the NHL season.
However, a report in the Finnish magazine Urheilulehti suggests that time frame could be even longer. Sections of the story were translated for Josh Cooper of The Tennessean and indicate that Rinne is suffering from a serious infection that could do long-term damage to his hip.
"I don’t know about the timetable. First and foremost, we have to focus on getting the infection eliminated. I don’t want to guess, but I hope things get better as soon as possible," Rinne said.
In other words, Rinne isn’t likely to be healthy for at least four weeks. Depending how things go, it might be significantly longer than that before he’s ready to return to the team.
Rinne is a known quantity. He has been the Predators’ starting goalie since 2008-09. Over his career, he’s had both good and bad years, but overall has posted an exceptionally good .919 save percentage.
We know less about Rinne’s replacement, Carter Hutton. The 27-year-old saw his first minor league action in 2010 after spending four years in college hockey. In the years since, he has faced a little over 3,000 shots at the AHL level, posting a .911 save percentage.
Stephan Cooper of SBNation blog Eyes on the Prize has done some work to determine how the typical AHL goalie performs in the NHL. Goalie performance is far less stable than skater performance, so the individuals studied varied widely, but he found that on average an AHL goaltender will lose roughly seven points off his save percentage when he moves to the majors.
This means that a reasonable expected performance for Hutton would be in the .904 save percentage range.
Let’s try and express that difference in more concrete terms. The Predators average 29.5 shots against per game. Over an average 10 games with Rinne, they would expect to allow 24 goals. Over an average 10 games from a goalie with a .904 save percentage—our Hutton projection—they would expect to allow 28 goals.
Ten games is roughly equivalent to a month of NHL action, so if Rinne is out for only a month, then a four-goal shift isn’t likely to be the deciding factor in a league where the typical team scores well over 200 times in a season.
Moreover, Hutton’s early performance has had some ups and downs but has been broadly encouraging. Over five games, the rookie has a respectable .912 save percentage.
In the short term, the absence of Rinne is not a fatal blow.
Long-term, though, those extra four goals for every 10 games add up to a considerable figure. For the Predators' sake, it should be hoped that Rinne is only sidelined for a month. Nashville's early-season performance has them two points back of St. Louis for the final Central Division playoff spot, and there is precious little margin for error. A lengthy absence for Rinne would almost certainly exceed that margin.