The most celebrated Team USA roster in baseball history is going to need some help to advance out of pool play in the World Baseball Classic.

A stunning 8-6 loss to Team Italy at Daikin Park in Houston on Tuesday night left the Americans facing a potential tiebreaker to move on in the tournament. The pitching staff faltered, and the offense stalled early with many of its top hitters on the bench. Rather than bully its way into the quarterfinals, Team USA (3-1) is going to have to watch the scoreboard and hope for a blowout Wednesday.

Team Italy is now 3-0 in Pool B and faces Team Mexico (2-1) in the finale at 7 p.m. (ET) Wednesday. Here are the two scenarios at play:

If Italy wins, it will be the top seed out of Pool B, and Team USA will advance as the second-place finisher.
If Mexico beats Italy, all three teams will finish 3-1 with room for only two to advance to the quarterfinals. The first tiebreaker is head-to-head record, but that won’t matter (each team will be 1-1 head-to-head). According to the WBC website, the second tiebreaker is: “the lowest quotient of fewest runs allowed divided by the number of defensive outs recorded in the games in that round between the teams tied.” Basically, the fewest runs per out in head-to-head games.

Team USA recorded 54 outs and allowed 11 runs against Italy and Mexico (.2037 runs per out). Mexico got 24 outs against Team USA and allowed five runs (.2083 runs per out). Team Italy allowed six runs while recording 27 outs against Team USA on Tuesday (.2222 runs per out).

So, for Team USA to advance, it needs one of two things to happen Wednesday: either Team Italy wins — in which case, the score doesn’t matter — or Team Mexico wins a high-scoring game while allowing or scoring at least six runs. The easiest way for Team Italy to advance is to simply win its final game, which makes the tiebreakers moot.

Team Mexico needs to win without allowing more than five runs. If the game were to go to extra innings, then the same quotient would apply.

That sort of minutia wasn’t supposed to matter for the Americans. Team USA came into the tournament with its roster loaded like never before. There were the usual big bats — Aaron Judge, Bobby Witt Jr., Cal Raleigh, etc. — but for the first time, several top American pitchers also joined the squad. Logan Webb, Tarik Skubal and Paul Skenes started the first three games of pool play and had Team USA on the verge of marching undefeated into the quarterfinals.

But everything faltered in Game 4.

Manager Mark DeRosa rested many of his top hitters — Raleigh, Bryce Harper, Alex Bregman and Byron Buxton were each on the bench to start the game — and had his least experienced starter on the mound. New York Mets prospect Nolan McLean started for Team USA and allowed a pair of home runs in the second inning, first to Chicago White Sox catcher Kyle Teel and then to White Sox prospect Sam Antonacci.

Kansas City Royals outfielder Jac Caglianone added a two-run homer off New York Yankees reliever Ryan Yarborough in the fourth inning, and Team Italy marched to an early 5-0 lead. That was plenty for Team Italy starter Michael Lorenzen.

One of the most accomplished pitchers on the Italian staff, the veteran Lorenzen shut down the vaunted American lineup through 4 2/3 scoreless innings. He struck out two and allowed just two hits. Team USA got back into the game against the less established Italian bullpen — Gunnar Henderson homered, and Pete Crow-Armstrong went deep twice — but Team Italy tacked on against the U.S. bullpen and had enough wiggle room to withstand the American onslaught, even as Team USA twice brought the tying run to the plate in the bottom of the ninth inning. Boston Red Sox reliever Greg Weissert struck out Henderson and Judge to end it.

Now, Team USA has to sit, watch and hope for a slugfest if it’s going to advance to the knockout stage.