The Milwaukee Bucks fell 139-122 Tuesday night against the Philadelphia 76ers and after the game Milwaukee head coach Doc Rivers had just one thing on his mind that he knows led to the loss: poor defense. 

Rivers came right out of the gate in his postgame interview and said that Milwaukee's defense was "awful" and pointed a number of specifics after the fact that backed up his point. 

The Bucks were specifically outclassed when it came to rebounding with 38 boards to the 76ers' 46 and the discrepancy was even more glaring when it came to offensive boards.

Milwaukee had just eight offensive rebounds compared to 15 by Philadelphia and it was this area that had Rivers the most upset. 

It was a high-scoring offensive game for the Bucks with 122 points, which only makes their defensive struggles all the more glaring by giving up a massive 139 points to the 76ers.

Despite the loss, Rivers had good things to say about several of the scoring performances in the game, with Myles Turner and Kyle Kuzma drawing the most praise. 

Turner had a team-leading 31 points with both Kuzma and Bobby Portis scoring 17 points each.  Their standout offensive games made the loss and the Bucks' lack of defense all the more frustrating for Rivers as he saw the team's preparation and priorities go out the window once action actually started. 

This is the first game, and loss, for Milwaukee since losing Giannis Antetokounmpo to injury once again and based on their track record from the last time that Antetokounmpo was injured, the team will have to make some major adjustments and dig deep to find an identity without their star on the court. 

The Bucks are now 18-27 on the season and robbed of their best player, it will surely be an uphill battle for the rest of the season. 

The way that Turner, Kuzma and Portis performed in the game is a good sign, at least, but the Bucks need a full team effort to pull together a win most nights, which has been a quality that the team has severely been lacking throughout the season. 

The potential is there for the Bucks to recover somewhat for the remainder of this season, but the clear lack of identity is a problem that has popped up since the beginning of the season and continues to plague them like it did in their loss against the 76ers. 

Rivers' frustration has been building with each loss and as the game plan crumbles with each game, the team's problems only grow.