My concern with Hinrich is next season and the year after. Not this season. It's the remaining years of his contract.
The concern is the finances and the need to sign a new main backup wing next season. That will be after paying the starting five roughly $61 million (Ray @ $6.5mil) and another $15 million for Wallace and Hinrich. Only seven players and the Celtics are already at $76 million with a likely luxury tax threshold of around $65 million. If the Celtics had minimum contracts throughout the rest of the roster (15 man squad) they'd still be adding another $6.6 million. That would give a payroll of about $100 million after luxury taxes. Oh, and Glen Davis, and a draft pick, minus those two minimum contracts, so another $3.7 million after luxury taxes. $104 million.
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Actually, that's the wrong way to look at it ... or at least misleading by itself
(1) If the Celtics spend their MLE, and I fully expect them too, they'd be adding close to $6 million in salaries anyway. So Hinrich is only $3 million more than that, well doubled to $6 million ... so that's the difference financially.
(2) A Kirk Hinrich + Brad Miller led bench was a formidable combination against the Celts in the playoffs last season. A Rasheed Wallace + Kirk bench would be similarly strong only with more defense from their big man.
With those two playing a large chunk of the minutes and Davis cleaning up the second big man role, the Celtics would only need a 15 minute a night backup at SF. An Ime Udoka or Keith Bogans type. Even with a lesser player like Quinton Ross or Rodney Carney things could work out fairly well.
(3) Can you build a better bench with the MLE to sign a new backup guard and a new backup wing? A better unit than Kirk Hinrich + minimum contract wing + Glen Davis + Rasheed Wallace? The rest of the squad will be filled out with minimum contract players in either situation.
And if the Celtics were to use their MLE on a wing and then to re-sign House for say $2 million. The difference between that and Hinrich + a minimum contract wing closes further ($2mil doubled).
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Then Perkins contract is up in 2011 and will be looking for a large pay rise. But I expect the Celtics to use their MLE anyway so not much difference here (MLE increasing contract, Hinrich decreasing contract, so $1.5mil doubled).