Well, Eflin seems pretty interested in reaching free agency, but the mutual option means there is at least a framework for discussion before any other team can talk to him. He probably doesn't give them a discount though, and if they end up being sellers they'll have to trade him if he won't do a July deal. Because there's little chance he's actually taking that mutual option if he's performing.
And Nola likely also wants to reach free agency after next season. He already gave the Phillies their discount. And much as we've wish he was a more perfect "ace," he's already put up 1.5 WAR this year and is going to deserve a $20 million AAV deal, and probably a 5th year (or more). A bitter pill but if they don't keep him they'll just end up giving it to some other free agent.
In either case, the window for an extension that is advantageous for the team or buys them cheaper years of control as an alternative to arbitration has already passed. And I think the original topic was "young player" who might be worthy of extension.
In Nola's case I'd also want to be sure the team is heading in the same direction come the fall of 2023. Nice win tonight but this could still be a .450 team, and next year could still be yet another .500 team, and if so, Wheeler probably shouldn't even be on the 2024 roster, let alone Nola.
