Unless the front office feels confident in Koehler being our #5 to start the season AND feel good with our backup options of Hand/Nicolino/whoever, I'd say we need Eovaldi. Koehler becomes one hell of an insurance policy for any pitchers getting injured/performing poorly while also being incredibly useful in the bullpen until then.
Again, this is all under the assumption that Haren retires, and given the circumstances we shouldn't be expecting him to pitch in Miami even if decides to play again anyway (he'll be traded to the West Coast without a doubt).
This makes me think Haren is either close to a decision, close to being dealt, or is being pushed by the Marlins to make his decision sooner rather than later.
If Peavy is suddenly attracting more interest he won't be a free agent for long. And if our push for him is dependent on Haren he'd better hurry it up because Peavy isn't gonna wait forever once he gets an offer he likes.