Nope, no round 2 vs. Ghana, it all comes down to goals.
Win and we're in (obviously). Tie and we are in. Lose? Then things get interesting.
Because of Portugal getting stomped by Germany, they have the biggest hill to climb and have by far the longest odds. Ghana is a different story. First tie breaker is goal differential. If we lose by one and Ghana wins by two, they go through. If we lose by and one and they win by one, then it comes down to goals scored. After two games we've scored 4 goals to their 3. If they get two and we get none, they'd go through due to 5 scored for them vs. our 4.
Basically we want to win (bc fsck yeah, Murrica!), draw and/or pray for a very low scoring game between the other two in the group. As long as we also don't get curb stomped by Germany, a 1-0 Portugal win would suit us just fine.