There are a lot of reasons for the Phoenix Suns slow, inexorable drop into the all-too-familiar territory of losing streaks.

After a promising 7-4 start had basketball-reference.com giving the Suns a 99.8% chance to make the playoffs, they now find themselves with an 11-16 record, riding a four-game losing streak. Sure, most have been close losses — they still have positive overall point differential! — but they are losses nonetheless.

We can complain about refereeing. We can complain about drugs. We can complain about missing big shots. We can complain about bone-headed split-second decisions in game-deciding moments.

All of those contribute to losses.

But possibly the biggest deciding factor so far this season has been the availability of Devin Booker, Deandre Ayton, Ricky Rubio and Aron Baynes.

Those four have only played 1 game together this season and even three of the four have only played in 11 of the 26 other games.

Check it.

For those noticing, I embellished two instances. I included Booker among the injured in last Wednesday’s loss to the Grizzlies where he was noticeably affected by the forearm/wrist, and I included Rubio among the injured in that Boston loss where he limped through a terrible first half before missing the rest of the game and the next four.

You could argue that Kelly Oubre Jr. is among the team’s best four players, but I can’t agree. Yes, Oubre is third on the team in scoring and rebounding and he is definitely the flashiest guy on the floor. But I just believe the other four are more impactful in the win column.

Devin Booker and Deandre Ayton are the team’s most talented and productive players, while Ricky Rubio is the clear leader on offense and defense and Aron Baynes was a complete revelation for the first month of the season. It was Baynes missing time, along with the suspended Ayton, that really started the death spiral in the W-L column this year.

I do believe Monty’s “core four” are Rubio, Booker, Ayton and Baynes. In a perfect world of health, the Suns would have all four players in the rotation and at least two of them on the court at all times. But they have only been healthy together for one game this season on opening night, a 29-point win over full-squad Sacramento.

If even three of them play, the Suns are a pretty good team. In those games, the Suns are 5-6 with all six losses coming to teams contending for their conference finals. Their wins included putting down the previously-undefeated Sixers and they notched wins against every lesser team on what was the league’s toughest opening schedule.

The Suns 4-6 record when just two of the core four play is a bit soft, with only one win against at contender (Clippers) and bad losses to Washington, Orlando, Memphis, San Antonio and Portland who all had worse records than the Suns coming into the game.

When only one of the core four plays, the Suns have a paltry 1-3 record. Their lone win came that improbable Saturday afternoon in Minnesota and bad losses include the Pelicans and depleted Sacramento.

No offense to Kelly Oubre Jr. or Dario Saric or Frank Kaminsky or Mikal Bridges, but that combination of players cannot win games consistently by themselves. Rookie Cameron Johnson might rank 8th on your board ahead of Frank, but you get my drift. Those five have been healthy all year, but their record is 5-9 this season when there aren’t at least three better players on the court with them.

Bottom line

When 3 or 4 of the Suns core four play, they can compete with any contender and will notch wins over most everyone else. That’s a playoff team.

But when 2 or fewer of the core four play, they’re in big trouble.

Pray for health, Suns fans.