USA will take on England in the World Cup semifinal on Tuesday at 3 p.m. ET (FOX / Telemundo) and U.S. manager Jill Ellis has a big question that she needs to answer.

Who is going to be in her midfield?

So far this tournament, Ellis has used four midfielders in her three midfield spots. (The U.S. plays the four defender, three midfielder, three attacker system favored by many of the top teams in the world right now.) The four midfielders are Julie Ertz, Lindsey Horan, Rose Lavelle, and Sam Mewis.

Ellis can only start three of them. And this is going to be a nightmare of a decision.

Ertz is a defensive wrecking ball who covers a ton of ground and can drop back into the back line to protect a lead. (This is what happened in the last half hour of USA – France.)

Horan is the reigning NWSL MVP and the USWNT’s most complete midfielder. She can pass, dribble, defend … whatever. She’s arguably the best midfielder in the world. She didn’t start against France, and a lot of people (including mine own self) freaked out about it.

Rose Lavelle is a brilliant dribbler of the ball who, at times this tournament, has looked like the USWNT’s best player going forward. Sam Mewis was supposed to be the odd player out in this group entering the tournament, then went ahead and looked absolutely dominant every time she stepped on the field. She’s a physically imposing player who can attack and defend in equal measure, and has shown a great passing rapport with Megan Rapinoe on the left side of the field.

Lavelle and Mewis have played so well it forced Ellis to bench Horan against France, which seemed unthinkable, and the U.S. still got away with it, because Lavelle and Mewis are both fantastic.

Four players, three spots. And a really, really tough opponent in England.

Michael Chow-USA TODAY Sports

England has built an identity this World Cup of counter-pressing — swarming with players and trying to win the ball back quickly when they lose it. It wouldn’t surprise me if manager Phil Neville dialed that up even more in this match, encouraging the England players to press high and put pressure on the USA defenders and goalkeeper no matter where they are on the pitch.

Spain did this to success in their round of 16 match against the Americans, generating their one goal when they pushed extremely high and forced a turnover in front of the goal. The U.S. needed two PKs from Megan Rapinoe to escape from that one, and I’m guessing Neville will be watching that game film closely ahead of this match.

Can England do that for 90 minutes? I’m not sure. But my guess is they’ll try.

And this all leads to Ellis having to make a really tough call. Does she keep Lavelle, a talented dribbler who can break down a press with the ball at her feet, in the lineup? Does she bring back in Horan, a better passer and stronger physical player than Lavelle, to protect the ball and pass them out of pressure? Does it make sense to have three players who are more comfortable with the ball at their feet in Lavelle, Mewis and Horan, and thus keep Julie Ertz off (and sacrificing the defensive cover she provides)?

Ellis could, in theory, push Ertz into central defense, but even I will admit she’d be insane to break up the Becky Sauerbrunn – Abby Dahlkemper center back pairing that was so fantastic against France.

So, we’re left with four players, three spots, and no good answers. The easy choice would be taking off Lavelle, the youngest and most attack-minded of the four. I suspect that’s what Ellis will do. Lavelle can be fantastic if she gets the ball in open space, but if England is denying the passes into her feet (as France did), she becomes a luxury that the team might not be able to afford.

Michael Chow-USA TODAY Sports

Then again, this is the USWNT. They’re the most talented team in the tournament. Ellis may say screw it and insist that Lavelle stays on the field, precisely because she can break down England and, if she’s out, the U.S. could be sacrificing the ability to dribble through the English defense and generate the offense it needs.

As you can see, I’m going in circles. I haven’t loved many of Ellis’ decisions so far this tournament, but for this game at least, I don’t have any great answers. I think Horan needs to be in the lineup. I guess Ertz needs to be in there as well. Mewis has been just about perfect all tournament, so it’s hard to leave her out. I think it’s Lavelle who gets the short straw.

Unless it isn’t. I don’t envy the choice Ellis has to make.

UPDATE: We’ve got our answer. Mewis will be the one to sit.

Also, um, Megan Rapinoe isn’t starting.

[jwplayer z6Vjsx3W-q2aasYxh]