The blows for Buffalo Bills fans came in quick succession Tuesday night.

First was a shocking 33-word statement from general manager Doug Whaley that sent a clear message: brace for the worst with linebacker Kiko Alonso, who quickly had become a fan favorite and rising defensive star last season.

"We have learned tonight that Kiko Alonso injured his knee while working out in Oregon," Whaley said. "We do not have the details at this point, but early indications are that it may be significant."

Less than an hour later came confirmation, from ESPN NFL Insider Adam Schefter, of Bills' fans fears: Alonso had torn his ACL and is expected to miss the upcoming season.

At a time when those around the NFL are relaxing on beaches and boats, the stunning developments with Alonso have taken the wind out of the Bills' sails.

This is a crushing blow just more than two weeks before training camp begins.

Alonso was part of a defensive resurgence last season under former coordinator Mike Pettine, playing every defensive snap. The team moved him to weak-side linebacker this offseason, and its hope was that Alonso would take another step forward, helping to improve the Bills' run defense as a run-and-hit outside 'backer.

At this point, you can rip up those plans and toss them in the trash, at least for this season. The Bills are back to the drawing board at linebacker.

Luckily for them, the team made two low-cost, high-upside signings this offseason, bringing in Keith Rivers and Brandon Spikes. That shored up what was, aside from Alonso, a weaker point in their defense last season.

Before Alonso's injury, the Bills planned to start Rivers on the strong side and Spikes in the middle. With a hole potentially opening up on the weak side, they have several options.

First, they could move Rivers to the weak side. That would open a hole on the strong side, but Rivers has adequate range to play any of the three linebacker spots. He has an injury history that should make the Bills leery of relying too much on him, but at this point they might not have a choice.

Moving Rivers across the formation would require someone else moving into his old spot. One choice would be Preston Brown, a third-round pick who impressed at middle linebacker this spring. Having a rookie learning one position in organized team activities and another in training camp isn't ideal, but Brown has impressed coaches so far. The Bills could hold their breath and hope that Brown makes like Alonso and steps in without a hitch on the strong side.

If the Bills wanted to go with more experience in their second level, Manny Lawson is their best bet. Lawson, who turns 30 later this month, started 15 games last season at strong-side linebacker. That's a different position in Pettine's defense than it is for Schwartz, and Lawson would need to play off the line more than he did last season. Moving Lawson back to linebacker would also weaken the Bills' depth at defensive end, but it's an option they need to consider at this point.

Another possibility is to replace Alonso with Nigel Bradham, keeping Rivers on the strong side. Bradham, a former fourth-round pick, started 11 games in 2012 as part of a Bills defense that ranked 31st against the run. His playing time was cut considerably under Pettine last season, but he offers more athleticism than the alternatives at the position.

There are few, if any, remaining options on the free-agent market who could step in and start for Alonso. Any new player coming in would have to play catch-up to learn the defense. The Bills could add a veteran for depth during training camp, but they would likely keep the expectations low with any new addition.

Instead, the strongest bet is that Alonso's replacement is either Bradham, Brown or Lawson.

None is Alonso. After snagging four interceptions in his first four games, Alonso's on-field play and his nonchalant personality earned him "legend" status among Bills fans, who flocked to buy his jersey.

In a cruel offseason twist that came down like a bolt of lightning on a summer night, Alonso won't be wearing his jersey on the field this season.