Do the Celtics have cap room for an extension?
No. IT could get an extension that starts next year at about $7.5 million. This is a wasted thread.
I didnt consider this aspect
So the Celts cant pay him 20 million per year max extension, with Wyc having to pay the luxury tax?
Also why cany the Celts set up a pre extension like what Harden got from the Rockets with 2 years currently left in his contract?
Harden is eligible for the Designated Veteran Extension, which IT is not eligible for because a) he has not been in the league long enough (minimum 7 seasons) and b) has not been with the Celtics long enough (minimum 5 seasons).
You are allowed to renegotiate and extend a contract that has been signed meow than three years ago, for which IT would be eligible effective today, I believe, but only if you have the cap space to add to the contract. Otherwise it can just give a player a 20% raise next year.
If we had missed out on Hayward, it was very possible IT would have been given a renegotiation /extension at the reduced max price this year. But since we got Hayward, we have no cap room. I prefer Hayward, myself. IT will get paid next year. Ownership presumably has set a budget that allows them to pay the luxury tax next year if they signed a max player this summer, since they'll pay to be contenders.
Is Boston a contender though? And are they going to pay the tax for multiple seasons and become a repeater?
Yes, they're a contender, or they will likely see themselves as such beginning next summer. The Cavs very well could be in their final season this year. The Warriors advantage of Klay Thompson's deal ends a season later. So the window for this roster, with continued growth from some of the young players to support the vets, will open much wider during IT's next contract. They may still be a player away from being a true top tier team, but letting IT go would leave them two players away. I personally think Tatum can become (which is different from "will become") that star level talent by his third season.
And it will depend a bit upon what happens with Horford after this contract, and maybe Hayward if he opts out after three seasons, as to whether or not they become a repeater. They could dip down below the tax line for at least a season, and maybe two, before enough young guys get their second contracts to carry them back into the tax.
The one bit of leverage they would have with IT is if Smart takes that next step forward this season. The Celtics will likely be able to keep only one regardless, and if that occurs, Smart would be a cheaper option than IT if they both got their respective maxes. I don't find it too likely that such a thing will happen, but it's not impossible. (It would also make the Celtics a legit contender this season.)