However, hopes that the team would take a step forward in Doug Marrone's second year as head coach were dealt a potentially crushing blow Tuesday, a blow made all the more stinging by the fact that camp wasn't even underway when it happened.
As Ian Rapoport of NFL.com notes, Alonso suffered a potentially serious knee injury while working out in Oregon:
Bills general manager Doug Whaley released a short statement. "We have learned tonight that Kiko Alonso injured his knee while working out in Oregon. We do not have the details at this point, but early indications are that it may be significant."
Later, news from ESPN's Adam Schefter was even worse:
It's a hammer blow to the Bills defense. Alonso, who led the team (and finished third in the NFL) with 159 tackles in 2013, was set to kick to the weak side of the 4-3 front being implemented this year by new defensive coordinator Jim Schwartz.
He's by far the team's most rangy and athletic linebacker, and Alonso was being counted on as a defensive leader this season.
Now, it's scramble mode for the Bills. Mike Rodak of ESPN recently wrote that third-year pro Nigel Bradham was previously on the roster bubble, but if Alonso is out an extended amount of time, Bradham could go from the outside looking in to seeing significant defensive snaps this year.
The team could also move Keith Rivers, who was brought in during the offseason and expected to start on the strong side, across the formation. The 28-year-old has experience playing the position, but Rivers also has a lengthy injury history and isn't as rangy as he once was.
Another possible replacement for Alonso would be rookie Preston Brown, who Rodak wrote caught the eyes of coaches during OTAs:
You can sense that the Bills already have a comfort level with Brown running their defense. Brown, a third-round pick from Louisville, began OTAs as the third 'Mike' on the field, behind Brandon Spikes and Ty Powell. Yet when Spikes missed two practices, it was Brown who stepped in with the first team. He didn't look out of place. Asked last week to point out strengths and weaknesses of his defense, coordinator Jim Schwartz named Brown, without prompting, as a 'really good young player' who has 'done a really nice job through this.' By the end of OTAs, Brown saw more reps with the first-team nickel defense, which is where he could make the biggest impact in his rookie season.
It now looks like Brown might be playing a lot more than just in sub-packages.
Of course, that's not the Bills' only problem. Alonso is also their best coverage linebacker, and even if Brown steps into an every-down role, that still leaves one more hole to fill against the pass. Bradham or perhaps safety Da'Norris Searcy, who played some nickel linebacker for the Bills in 2013, could be considered.
There's still much to be settled, but at this point, one thing is certain: July has gotten off to a rotten start in Western New York.
Gary Davenport is an NFL Analyst at Bleacher Report and a member of the Fantasy Sports Writers Association and the Pro Football Writers of America. You can follow Gary on Twitter @IDPManor.