As quickly as the window of opportunity seemed to have swung open for the Edmonton Oilers in recent days, prompting some sportsbooks and fans to dub them Stanley Cup favorites, it was slammed shut on Sunday by the Vegas Golden Knights, who beat them 5-2 to win their second round series in six games.

With the powerhouse Boston Bruins and the Toronto Maple Leafs already bounced in the Eastern Conference and Colorado out in the Western Conference, the table seemed set. If the Oilers could find a way past the Golden Knights, who’d finished two points ahead of them in the regular season but who’d they’d beaten in three of four meetings, they’d be on their way. I believed that. You?

All in all, it set up as a pretty good shot for the Oilers to get back into the conference final and it was, even with the Golden Knights up in the series 3-2 when the teams hit the ice at a packed Rogers Place last night with fans fully expecting a seventh game back in Las Vegas. The buzz inside and outside the rink was reminiscent of 2006. But no. Not even close.

Here we are today with the Golden Knights moving on and the Oilers wondering what went wrong after 50 wins and 109 points leading up to the post-season. And while we’ll be talking about how and why things went sideways – from the inability to hold a lead to flawed goaltending and defensive play to how the team is constructed and the way the assembled talent was deployed, plus all of the X’s and O’s – in coming weeks, the story for me today is about opportunity lost.

“It’s still very raw,” coach Jay Woodcroft said in his post-game availability. “Obviously, our group is very disappointed for coming up short of our goal, which was to push this series to seven games. “There’s moments in that series that we feel we could execute it at a higher level, but you also have to tip your cap to the other team.

“They finished ahead of us in the standings, and I thought there are moments we want to have back and we’re going to have to learn from, to use this as the growth opportunity that it presents itself as for us as an organization to take a step.”

In the end, the Oilers had enough leads in the series, like 2-1 in the first three minutes last night, but couldn’t hold them. After getting past Los Angeles in six games in the first round, they didn’t get enough saves from Stuart Skinner, pulled three times against Las Vegas. The Oilers never found a way to build and keep momentum against the Golden Knights. What we’ve got here is a really good regular season that ended badly.

“Yeah, it hurts,” said Leon Draisaitl, who was nothing short of magnificent at times in these playoffs and finished with 13-5-18. “I don’t know. It’s tough to find words right now. Obviously, when you start a season, you’re in it to win it, and we’re at that stage if you don’t complete that, then it just feels like a failure or a wasted year almost. So that hurts.”

We’re into couch coach and armchair GM season now, the time when fans have a go at Ken Holland and Woodcroft and tell them what’s what – what to do with the goaltending, who to keep, who to move along, who to bring in. That comes with the gig. Might Holland bring in Steve Staios as GM and move to POHO? On the fringe, the Tin Foil Hat folks will find something to rage about – officiating will be high on that list. For now, it’s regret about what could’ve and maybe should’ve been.

“Feels like every team that wins and goes on a stretch of winning kind of experiences this,” said Connor McDavid, who tallied 10 points in the series and finished with 20 in the playoffs. “Obviously, it’s not what you want to do, not what you want to feel. That being said, I really feel you’ve got to go through some of this to win. I think we’ve seen that all the way through. So, let’s hope it’s the last time.”

With eight seasons in the books with the Oilers, this one marking personal career highs with 64-89-153, McDavid has good reason to feel that way. Likewise, Draisaitl. I’m guessing they’ve got lots of company – not only in the dressing room but with a fan base that’s been revved up and ready to roll only to be sent home wanting in back-to-back seasons.