1. Marc Gasol
I was conflicted with making Marc Gasol number one on this list as his value did turn around later in the year and his defensive metrics were always above-average, even when everyone was calling for his job.
At the end of the day, though, Gasol did not give the Lakers what they were hoping for and that is the entire reason why the team had to go out and get Drummond. The Lakers actively chose to let both Howard and McGee walk so they could get Gasol and it ended up being a big mistake.
Gasol played worse than either of those two players and quite frankly, it would have made more sense for the Lakers to simply run it back with the centers they had last season. The team was betting on the veteran ceiling of Gasol as well as his ability to space the floor and it just did not come to fruition.
There were some warning signs as well. While it was silly to expect Gasol at his best at his age, he still produced solid numbers overall last year. However, the warning signs came in the NBA bubble, where Gasol played really poorly and that translated over to the Lakers this season.
Ironically enough, Gasol became a better scheme fit for the Lakers against the Suns as he started getting playing time in the series but he did not impact the series enough for his season to not be considered a big disappointment.
When you consider what the Los Angeles Lakers gave up to get Gasol, it is clear he is the biggest disappointment of the season.