I think "the Phillies need a Game 3 starter" is kind of a false construct.
First they need enough pitching to actually win the wild card.
Second, they need to win it by 2-3 games so the rotation lines up.
And if both of those things happen, getting a great start out of one of the best version of Suarez, the best version of Gibson and Thor (with good rest/innings limit) is possible. If Eflin's back, bonus.
What "Game 3 starter" really means is someone you might trust to go through the order a third time, but in a clinching playoff series game I'm not sure there are many pitchers who would actually get to do that who aren't more like #1s. I hope the Phillies get that guy next season but getting one this season clearly a Catch-22 (i.e, "the Phillies aren't good enough to make that kind of trade" vs. "that kind of trade would make the Phillies good enough.")