From the moment Nat Borchers collapsed to the turf at Providence Park on Saturday, it seemed more likely than not that his 2016 season was over.

On Monday morning, those fears were confirmed: The beloved center back, the heart and soul of the club's 2015 MLS Cup championship, has a ruptured left Achilles tendon. He'll have surgery in the coming days, and won't play again this year.

The injury is one of the most excruciatingly painful an athlete can suffer — and at 35 years old, with his contract due to expire at the end of the season, Borchers' future with the Timbers and as a professional soccer player is uncertain at best.

It's an almost unbearably cruel fate for one of MLS' most well-liked and well-respected players. Considering Borchers' extraordinary durability over his long career, this is an especially low blow.

In an immediate competitive sense, this injury deals a severe blow to the Timbers' chances of repeating as champions this season. All year long, the team has only one won game in which either Borchers or Liam Ridgewell didn't start.

The Timbers, in the ten games which either player missed, have picked up just seven points. The defense that was the backbone of Portland's 2015 success, already down Jorge Villafaña, has now been irrevocably torn apart.

The idea that Borchers wasn't playing well this season was mostly a myth. Considering the team's failure to replace Villafaña at left back, and Ridgewell's inability to stay healthy, the Timbers' defense was always bound to regress. Borchers wasn't the problem. His play this year remained heady, consistent, and tough. He was, if anything this year, slightly luckless and consistently let down by the players around him.

Caleb Porter may have been fixing to replace Borchers in the lineup even before his injury. Former Newcastle United defender Steven Taylor was at Providence Park taking in the game against the Los Angeles Galaxy on Saturday, and he's expected to sign with the team in the coming days.

But Taylor hasn't played more than ten games in a season since 2012-2013 in the Premier League, and until he's ready to play, the Timbers will have to turn again to the carcass of Jermaine Taylor to fill in.

Amobi Okugo, signed as a reclamation project earlier in the year, figures to factor in as well. With Ridgewell set to be suspended for next weekend's game at Sporting Kansas City by virtue of missing the MLS All-Star Game on Thursday night, Okugo is slated to make his first MLS start in a year and a half.

Whether Ridgewell can truly be counted on down the stretch anyway remains to be seen. The captain has had problems with his calf all season.

These are dire straits for the Timbers. Backlines need reps together to develop chemistry. The reason Portland was so good defensively last year was that it had the same first-choice defense from Opening Day to MLS Cup. Ridgewell, you might remember, was significantly less impressive in 2014 when paired with Norberto Paparatto or Pa Modou Kah.

Interestingly, it was the club's failure to retain Paparatto — along with the ill-fated signing of Chris Klute to replace Villafaña — that has been its biggest front-office failing this year. The Timbers would give plenty to have the Argentine to fill in for Borchers right now.

The hope is that Taylor can come in and be the second coming of his soon-to-be English colleague Ridgewell. Even if that happens, the Timbers will still likely be taking a step back defensively. Borchers was one of the best center backs in the league.

It'd be easy — and maybe prudent — to write Borchers' professional obituary today. But if anyone can recover from an injury of this magnitude, it's him. Not only is Borchers a terrific competitor, but he loves being a soccer player as much or more than most. If at all possible, he won't let his career end like this.

And if he does get back to full fitness in 2017, Borchers should have a home with the Timbers. There's no telling that he won't be able to get back to his best, and even if he's not as a starter, there are few players in the league more valuable to have around a locker-room.

Saturday was the Timbers' darkest hour since the Cup was lifted last year. Winning the title with Nat Borchers was hard enough. Winning it without him will be, in all likelihood, very near impossible.