Barring a huge surprise, Zac MacMath will become the youngest goalkeeper to start a MLS game this season on Wednesday when the Philadelphia Union host the New England Revolution. Starting goalkeeper Faryd Mondragon is expected to be out four weeks with a broken right index finger, clearing the way for MacMath to see some significant playing time as the Union make their final push for the playoffs.
As recently as a few weeks ago, the Union seemed a lock for their first ever playoff berth. But after six straight weeks without a win, their postseason participation is no longer looking like such a guarantee, as they sit just two points ahead of the final playoff spot. How MacMath performs in Mondragon's stead will likely be a major determining factor for whether or not the Union are playing beyond Oct. 20.
How big the shoes MacMath has to fill is very much an open question, though.
That the Union are even in a position to be talking about the playoffs at this point in the season is largely credited to Mondragon. The Union are allowing .54 goals-per-game fewer than they did in 2010, which is the second biggest improvement in MLS. The most obvious change from a year ago is the 40-year-old Colombian, who until Saturday, had played every minute of every game.
Mondragon's periphery numbers lend credence to this theory. His 1.06 goals against average is the fourth best in the league among goalkeepers with at least 1,000 minutes played and his seven shutouts are the fifth most.
Digging a little deeper into Mondragon's numbers, we find some signs that maybe the Union's turnaround is not quite as much about his performance as it is about an overall improvement from the defense. Mondragon's save percentage, for instance, is just 61 percent. Among goalkeepers who have started at least five matches, no one is worse. In fact, Mondragon's save percentage is so pedestrian that last year's Union goalkeepers -- the ones that were deemed so bad that none of them were brought back this season -- were collectively better by that metric.
The biggest difference between last year's team and this year's incarnation is the number of shots the goalkeeper is forced to save. The 2010 Union goalkeepers faced 4.9 shots on goal per game, while this year's goalkeepers have faced 3.0. Based on a historical average of 25.8 percent of shots on goal turning into goals in MLS, the Union would have been expected to improve by .49 goals per game no matter who was in goal.
From a purely shot-stopping perspective, there is reason to believe that MacMath could actually be an upgrade over the man 20 years his senior. At every age level, MacMath has been among the best goalkeepers in the country. He has been a starter on U-17, U-20 and U-23 teams, as well as a three-year starter at the University of Maryland. He has been lauded for impeccable physical and technical abilities, registering shutouts in more than half of his collegiate appearances. Many believe he could very well be the next great American goalkeeper.
As we all know, though, shot-stopping is only part of the goalkeeping equation.
Let's assume for a second that MacMath is able to stop 15 percent more shots than Mondragon. If the Union were to keep up their pace of 3.0 shots-on-goal-allowed per game, MacMath could theoretically prevent two more goals than Mondragon over the course of five games. But if the Union were to continue to allow 4.5 shots-on-goal per game (as they have over the past six games), MacMath's improved shot-stopping would be negated, as even with stopping 75 percent of those shots the Union would be expected to allow roughly the same number of goals as Mondragon has while facing 3.0 shots per game.
It's in helping limit the opposition's opportunities that Mondragon really seems to have shined, at least until recently. The Union back four is about 50 percent unchanged from last year. Danny Califf was and is a mainstay at one of the center back spots and Sheanon Williams had established himself as a starter toward the end of last year. Carlos Valdes is the only player on their backline who has started the majority of this year's games that was not on the team a year ago.
If Mondragon deserves any credit, then, it would seem to be in his ability to organize those backline players. Incidentally, that organization has not been quite as good ever since starting left back Jordan Harvey was traded to the Vancouver Whitecaps. In the eight games played since the trade, the Union have been allowing about more than .25 goals per game than they had before the trade. At least part of the problem is that the Union went from allowing 2.3 shots on goal per game during their first 19 matches, to allowing 4.5 in their previous six.
How MacMath fares in this area will likely determine how successful he is. With Mondragon playing every minute of every game, no matter how much MacMath has worked with the first-team defense in training, there's just no way he has the same innate sense of where his defenders need to be and what they should be doing. MacMath reportedly watches film alongside Mondragon, but it's hard to imagine that studying tape is any substitute for actual playing time. It's these kinds of details which have historically contributed to goalkeepers hitting their prime later in their careers than players at other positions.
Making MacMath's job all the more difficult is the unsettled nature of Harvey's old left back position. Gabriel Farfan has received the bulk of the playing time there, but his twin brother Michael started the last game. Neither are natural left backs, in fact both are really attack-minded midfielders. They have both factored into defensive breakdowns in recent weeks, and having a relatively inexperienced goalkeeper behind them is unlikely to help the situation.
On the other hand, Carlos Valdes will be back after serving a one-game suspension for yellow-card accumulation. The Colombian has been the Union's best defender much of the year and keeping him on the field could be even more important than MacMath's play.
What we're left with is this: MacMath could very well end up being an upgrade over Mondragon in the shot-stopping category, and still allow as many or more goals than Mondragon has. As counter-intuitive as it may seem, MacMath may actually have to be an upgrade over Mondragon in both shot-stopping and shot-prevention for the Union to regain their form of earlier this year.
Maybe MacMath is up to the task. It's just that the task may be even bigger than we even thought.