Auston Trusty is following in the footsteps of fellow back line member Keegan Rosenberry this season. If he plays the full ninety minutes this weekend against NYCFC, Trusty will be the second Union first year player in three years to play every minute of the season for a playoff team.
Next to Trusty, the Union have rotated Jack Elliott and Mark McKenzie almost completely evenly throughout the season. If McKenzie starts this Sunday against New York City FC, he will finish the year with 18 starts to Elliott’s 16. One intriguing question to explore, then, is how the Union have performed with each of these center back pairings. The issue is particularly relevant with a win-or-go-home playoff match looming.
U good? U good
The most reassuring numbers to come out of this analysis are the goals conceded stats. Whether Philly have played with McKenzie or Elliott, they have conceded about the same number of goals per match: approximately 1.4. There is a slight difference in Goals Conceded In The Box, with the McKenzie/Trusty (M-T) duo allowing 1.35 per game to Elliott and Trusty’s (E-T) 1.2. But keep in mind that Opta counts penalties as shots in the box.
Not much between them
Also reassuring? Trusty himself comes out looking like a very similar player whether paired with McKenzie or Elliott. The young center back touches the ball about 56 times per match regardless of who his partner is, and he faces just over 12 shots per match no matter who is beside him in defense.
In terms of defensive actions, Trusty looks slightly more involved and successful defensively with McKenzie next to him. With McKenzie, Trusty averages about 2.4 aerial duels won and 1.4 lost, but with Elliott those numbers are 2.1 won and 1.9 lost. Trusty also makes about 1.8 tackles with McKenzie and only 1.4 with Elliott.
Alongside his homegrown partner, Trusty averages a 66% overall duel success rate, but that number drops to only 53% with Elliott, which could suggest that Trusty ends up in more difficult duels alongside Elliott or that teams look to target Trusty with better players more when he is paired with Elliott.
Trusty also appears to be a slightly more accurate long passer alongside McKenzie, averaging a 47.8% completion rate on balls into the final third while only averaging a 39.2% success rate with Elliott.
Regardless of who he plays with, Trusty loses the ball (including clearing it out of the back) about 11.5 times per match.
One notable difference between partners is that Trusty tends to be on the ball more in his own half when paired with Elliott compared to McKenzie. He attempts about 26.2 passes per match in his own half with Elliott and only 24.4 with McKenzie.
Overall, the biggest takeaway for Trusty is that he tends to be very consistent and comfortable with either center back partner. That should give the Union confidence with their options going into the postseason.
McKenzie and Elliott - Similar but different
There are clear differences in how Mark McKenzie and Jack Elliott approach their role in back, but they tend to be more on the attacking end than the defensive side of the ball.
For instance, the largest defensive gaps tend to be quite small. McKenzie averages about half an interception more per match than Elliott (1.6 to 1.1) while Elliott engages in about 0.6 more aerial duels than McKenzie (2.7 to 2.1). McKenzie wins, on average, 1.2 of his aerial duels while Elliott wins about 1.6. Elliott makes a little over six recoveries per match while McKenzie is at just a shade over five-and-a-half.
With the ball, though, these players take slightly different approaches. Elliott spends more time on the ball than McKenzie, averaging 64 touches to McKenzie’s 50. The big Brit also makes about five more passes in his own half per match than McKenzie (33 to 28). McKenzie is a bit less likely to hit the ball upfield, only losing possession on long kicks forward five times per match to Elliott’s 10. McKenzie is also accurate with about 49% of his passes into the final third of the field while Elliott is at 43%. Both defenders are hovering at around a 60% duel success rate.
Once again, it’s hard to argue that one player has been particularly better than the other. In fact, it seems that Jim Curtin has likely been justified in riding the hot hand this season and switching between McKenzie and Elliott as each grabbed their chances throughout the season.
Finally, let’s take a quick-n-dirty look at the Union’s opponents through the lens of Expected Goals. Overall, when the Union have used Mark McKenzie they have faced a slightly higher quality opponent. The average Expected Goals For across Union opponents when McKenzie starts is 1.56 expected goals per match. For opponents the Union faces with Elliott in the lineup, the average Expected Goals For is 1.39 expected goals per match. Remember that overall, the Union have conceded approximately 1.4 goals per game regardless of center back pairing.
If we look at game-by-game Expected Goals Against for the Union, we can get a rough estimate of how well the Union have defended independent of how many goals they actually conceded. This shows us that with McKenzie in the lineup, the Union have a slightly higher Expected Goals Against (1.71 per match if you include the nine-match game against Atlanta, 1.51 if you exclude it) than when Elliott is in the lineup (1.29 Expected Goals Against).
So Elliott has faced a slightly less threatening set of opponents this season (1.39 xG on average) compared to McKenzie (1.56 xG) and, correspondingly, the Union have a slightly lower Expected Goals Conceded per match with Elliott (1.29) than with McKenzie (1.51 without the Atlanta craziness).
What this all means is that the Union have been a fairly good defensive team regardless of who they have paired with stalwart Auston Trusty. Currently, American Soccer Analysis’ model shows the Union have the ninth best Expected Goals Conceded in the league. That’s good regardless of context, but it’s downright impressive considering that a) Auston Trusty has started every match in his first season, b) Curtin has had to follow his gut on who to partner with Trusty as the year has gone on, c) Keegan Rosenberry was by no means a guaranteed success story when the season began but has become vital to the attack and cleaned up the defensive issues that saw him relegated to the bench in 2017, d) the left back is a right back playing out of position, and e) Philly does not deploy a designated destroyer in front of the back four.
While the other teams fighting for the same playoff spots in the Eastern Conference have brought in expensive veteran defenders like Rod Fanni, Michael Mancienne (to name one of the Revs’ heavy defensive investments, and Jonathan Mensah, Philly went all-in on players they felt they knew well and could develop.
And no matter who lines up next to Auston Trusty in the playoffs, Philly will know they have enough defensive strength to take a good swing at a postseason run.