Geoff Cameron has been a mainstay in the US national team lineup for years, most recently crafting a sturdy partnership with John Brooks that has made them Jurgen Klinsmann's preferred center-back pair in 2016. The former Houston Dynamo star has started every World Cup qualifier in the current cycle as well as all six of the USMNT's Copa America Centenario matches.
But in all likelihood Cameron will miss out on this month's crucial qualifiers vs. Mexico and Costa Rica, hampered by a lingering knee issue that has ruled him out of Stoke City's last two Premier League matches, including Saturday's 1-1 draw at West Ham.
So where will Klinsmann turn to patch the big hole Cameron's absence would leave in the US back line? It's expected to come down to one of several current and former MLSers. Here's a rundown of the leading options – though we won't know the short list for certain until the US roster is announced on Sunday, at halftime of the Audi 2016 MLS Cup Playoffs game between the New York Red Bulls and Montreal Impact (approx. 5:10 pm ET).
Matt Besler: Mr. Reliable
Sporting Kansas City's long-serving veteran is composed and experienced, USA-Mexico games included. He featured in last year's CONCACAF Cup showdown at the Rose Bowl and anchored the resistance that earned the Yanks a 0-0 draw at Estadio Azteca during the last Hexagonal. He's started seven of the USMNT's 17 games to date this year, including a 90-minute outing in their most recent match, last month's 1-1 friendly draw with New Zealand.
Besler earned warm praise from Klinsmann after that one, the German even going so far as to publicly ponder why he'd recently spent so much time on the SKC bench. And that brings us to his biggest disadvantage. Citing a slip in his form, coach Peter Vermes only started Besler in seven of Sporting's final 14 MLS matches, including their contentious Knockout Round loss to Seattle in the postseason.
If called in, the Notre Dame product will have just a few training sessions to convince Klinsmann that it hasn't affected his preparedness for Mexico.
Omar Gonzalez: Tower of power
The former LA Galaxy Designated Player has carved out an impressive career in Liga MX since his head-turning transfer to Pachuca last December. He immediately helped Los Tuzoswin the Clausura championship, adding a cultured polish to his dominating physical attributes.
His case is further bolstered by his rugged work in previous border clashes – he was Besler's partner on that memorable night in Mexico City three years ago – and the menace his height offers on attacking set pieces. And he'll be familiar with El Tri's domestic-based players.
But Gonzalez seemed to suffer for his part in March's upset qualifying loss at Guatemala, as he was subsequently left off the Copa America roster and did not play for the US again until September's win over Trinidad & Tobago. Has he earned Klinsmann's trust back?
Steve Birnbaum: Smooth operator
After struggling at times in his second pro campaign in 2015, D.C. United's rising star has enjoyed a resurgent year that's pushed him right back into the USMNT mix. He's been an ever-present in Ben Olsen's XI in D.C., starting in 26 of the 28 MLS games he was available for and drawing plenty of interest from clubs overseas.
Klinsmann seems to appreciate Birnbaum's passing range as well as his aerial ability. He might be a good option for the cerebral task of tracking the movement of elusive Mexican striker Javier “Chicharito” Hernandez. But the Californian still only has seven caps on his resume, so this border clash might come too soon in his international career.
Michael Orozco: The dark horse
Orozco has been earning regular minutes for Liga MX leaders Club Tijuana. He's versatile. And he is quite versed in the USA vs. Mexico rivalry, most notably as the scorer of the winning goal in the Yanks' historic friendly win over El Tri at Azteca – their first in 25 attempts – in 2012, a feat that's earned him the nickname “Historical Gringo” among his club teammates.
The ex-Philadelphia Union man isn't universally appreciated among USMNT fans, however, probably because he's a utility man who is steady but rarely spectacular in any one respect. But he's a trusted Klinsmann regular. Don't be surprised if Orozco is handed a bigger role in Columbus than many expect.