And that shows up particularly on the defensive line where the 38-year-old Keith Traylor wears down but no longer has a quality backup behind him because fourth-round pick Paul Soliai isn't ready to make an impact yet.
It shows at left defensive end where Matt Roth's lack of size has made him an absolute non-factor through three games as the replacement for Kevin Carter, as we had feared.
Roth was really good in the preseason, but does anyone remember him making a play in the first three games?
The biggest concern, though, just might be Jason Taylor, who has looked nothing like a returning NFL Defensive Player of the Year.
In three games, Taylor has exactly one sack, and that was a coverage sack against Washington. He has no interceptions, no forced fumbles, no fumble recoveries.
Yes, Taylor is getting a lot of attention from opposing offenses, but we saw him matched up one-on-one several times Sunday against Jets left tackle D'Brickashaw Ferguson, and Ferguson won practically every battle.
The issues up front have exposed a mediocre secondary, which sadly lost its best player (Yeremiah Bell) in the opener.
On top of all that, the Dolphins had to face the Jets without Zach Thomas, who was the Dolphins' best player through two games. The feeling is Thomas' latest concussion wasn't that severe, but it's disconcerting that he's had a lot of them and he's 34 years old.
Put everything together, and it's not a pretty picture for the Dolphins defense.
The Jets offense is not particularly explosive, yet they moved the ball at will on the last drive of the first half and the first two of the second half.
The start of the season has been remarkably depressing for the Dolphins, and maybe what's worst of all is that the defense no longer is a strength and might even be a weaknee.