Jurgen Klinsmann debuts as head coach of the U.S. national team tonight against bitter rival Mexico.

His starting lineup appears to be a 4-2-3-1, with Landon Donovan and Jose Torres running the wings and Michael Bradley stepping into an attacking role.

Michael Orozco Fiscal, Torres and Edgar Castillo all in the lineup. Follow along with the action here.

FINAL, USA 1 - MEXICO 1: After a poor first half in which they could generate little, the U.S. was energized by its substitutions beginning with the introduction of Juan Agudelo and Brek Shea in the 59th minute. Part of that probably had to do with players going into positions that suit them better (Torres central, Bradley in defensive center mid), and part was the energy that Shea and Agudelo immediately brought.

The subs paid off in a big way one minute after Robbie Rogers was introduced, as Agudelo played Shea and he beat two defenders to feed a wide open Rogers on the far post for the equalizer.

Credit to those younger players for what they brought to the field when they entered, and for the U.S. to find its way after a rough first hour. They created a ton of chances late and could walk off the field feeling relatively positive.

Keep it tuned in here for a postgame blog including...player ratings! Tweet me your thoughts, @PaulTenorio. Thanks for joining in the conversation here...

86’ - Agudelo sends Robbie Rogers in on goal, Rogers outraces his defender, Torrado, who pulls him down but referee somehow awards just a yellow. Looked like a certain red. Wow. Rogers was in on net.

84’ - Ricardo Clark in for Jose Torres. U.S. has gone to basically a 4-1-3-2, though this sub likely shifts it back to a 4-4-2.

82’ - Torres heads down to Donovan who plays Shea through on a great ball. Shea looks to far post but Ochoa pushes the effort away. Shea and Donovan combining nicely.

82’ - Torres has looked far more comfortable since moving into the middle. In general, the subs have done a better job of movement on and off the ball. More overlapping, players going inside and out. Just look more active.

77’ - Shea has brought a ton of energy since entering and has looked very confident on the ball. Showed on the goal. U.S. has had two nice attacks since the goal, Torres missed the upper corner and Donovan used his speed to break through but cut in hoping for a foul and didn’t get one.

73’ - GOAL! USA. Throw in to Agudelo near end line, he touches it back to Shea who muscles past defenders and finds Robbie Rogers alone on far post for the equalizer. Talk about super subs. All three came in as subs. USA 1 - MEXICO 1

72’ - Robbie Rogers on for Michael Bradley. Think this moves U.S. to a 4-4-2 lineup with Donovan pushing forward...

68’ - Agudelo makes a good run and gets ball on left wing but has no support. Dribbles out of bounds as he has to try to beat three defenders.

62’ - Agudelo makes a run as Shea overlaps. Agudelo shot way over the top. Still, a little life and off the ball movement.

59’ - Brek Shea and Juan Agudelo enter for Jermain Jones and Juan Agudelo.

56’ - U.S. with its best chance of the night. A Landon Donovan corner is headed with power from eight yards out by Bocanegra, but Ochoa with the save.

53’ - Mexico has a solid scoring opportunity, as a Marquez header just missed the far post. Mexico brings in two subs in the 55th. Dos Santos enters for Naelson.

47’ - We’re back. I just finished a lively debate with The Sporting News' Brian Straus about idea of this formation, how it should be run, how it was run and where it was going wrong. One thing for sure: plenty to argue about. Still, as one tweter pointed out, it’s Day 2 in a new system. We’ll see if much changes in the second half.

HALFTIME, MEXICO 1 - USA 0: U.S. was much better in the last eight to 10 minutes of the first half. In the early going they lacked shape on both sides of the ball, losing players with poor spacing defensively and lacking an idea going forward. Still, they surrendered few solid chances on Howard’s net.

As the half wore on, the Americans started to find purpose going forward. Outside backs played higher and that allowed Donovan to get on the ball more. Still no chances were created. Michael Bradley didn’t look wholly comfortable in his new attacking role, but did look to take charge at points when U.S. needed it most.

What changes do you think will be made, or should be made, in the second half? Tweet me at @PaulTenorio.

40’ - U.S. starting to find its shape a bit more. Outside backs getting high, Jermaine Jones dropping in, Torres and Donovan pinching high and more central. The result: U.S. gets forward with more numbers, Cherundolo cross. Looked better.

35’ - Mexico still controlling possession, but not a ton of chances created yet. U.S. spacing has been erratic at time. Chalk it up to new formations? New players? New partnerships? All of the above, probably. Gotta get it sorted out. Bradley starting to try to cover more ground, dropping deeper.

30’ - Shoving match on the field between U.S. and Mexican players. Two of them shove Cherundolo, one threw a backhand slap. Referees break it up, but somehow no cards handed out.

25’ - Mexico is controlling possession and right now the U.S. hasn’t shown any sort of assured idea of how to go forward. No one “running the show” so to speak, flank play not standing out either.

17’ - GOAL! Mexico scores first. Andres Guardado cross from the right side is lasered in and Mexican forward Oribe Peralta gets his foot around Michael Bradley to poke it to far post. Immediate reaction was too much space given on wing, but Peralta did an unbelievable job getting his leg around Bradley to redirect the ball. 1-0 MEXICO

16’ - Keeping an eye on the movements defensively on the outside, specifically the responsibilities and spacing between the midfielders — Donovan and Torres — and the outside backs, Castillo and Cherundolo. Castillo not afraid to get forward and has shown great speed, but dove in and gave up a counter in the 12th. He also just stepped up big in the 15th to save a quick through ball when Jermaine Jones got caught a bit too high. Right now Mexico holding the ball much better than U.S.

11’ - Perhaps one of the more surprising lineup decisions was Tim Ream not even dressing. Wonder how much Klinsmann just wanted to see Orozco Fiscal, or if maybe he felt it was a better match-up with smaller, quicker Mexican forwards. U.S. had a solid chance in the sixth minute on Landon Donovan’s cross that Edson Buddle just missed with a header and Jermaine Jones nearly caught up to. Mexican crowd singing “ole” but much of the passing happening out of the back.

1’ - And we’re off here in Philadelphia. This formation is slightly different than the five-man midfield formations the U.S. has run in the past. Here it’s a 4-2-3-1, with Michael Bradley sliding forward into a No. 10 type role. The U.S. will likely look to take advantage of the wings with Donovan and Torres and Buddle sitting high as a target striker.

Lineup after the jump.

USA LINEUP: Howard; Cherundolo, Orozco Fiscal, Bocanegra (capt.), Castillo; Jones, Beckerman; Donovan, Bradley, Torres; Buddle.

Subs: Hamid, Loyd, Pearce, Clark, Rogers, Shea, Agudelo.

Not in uniform: Adu, Ream, Beasley.

MEXICO LINEUP: Ochoa; Salcido, Marquez, Moreno, Juarez; Torrado, Castro, Naelson, Torrado, Guardado; Peralta.