If the US manages to come in second in their group (looking like ~75% or so) there's a good chance the draw opens up decently for them. Assuming they finish second in Group A, here's a look at how their draw could potentially open up:
-Group B: Brazil is currently a slight favorite to win their group in the betting markets (~52-55%). As runner ups, the US would play the winner of this group. Both Ecuador and Peru have a solid shot to win the group (~21-25%). Obviously, either one of those two nations emerging as the group winner instead of Brazil would be a very preferable outcome for team USA, and the chances of that happening are surprisingly high (at least to me).
-Group C: Mexico is a solid favorite to win (~75%). Personally, I'd rather potentially face Uruguay than Mexico in the quarterfinals, although Suarez's potential return looms as a big boost for the Uruguayans. But Uruguay currently have roughly the same chance of winning the group as Venezuela (a little over 10% for both sides)
Group D: Argentina are well over 90% to win this group, with Chile more likely than Panama to come in second. Chile are the stronger side, and though they trail Panama in points 3 to 0, they will be favored to win both remaining matches against Panama and Bolivia.
Not to get too far ahead of everything, as the US obviously still has to actually secure their advancement. But securing a draw of Ecuador/Peru, Mexico/Urugary, and Panama/Chile would be very favorable, especially with the first head to head coming against either Ecuardo or Peru. Something to keep an eye on (and root for if you're pulling for the US) as the group stage matches play out.