With Skubal gone I think that leaves Detmers, Holmes or Gausman as possible fits for the Brewers. There are others but I think these are the top 3 for the Brewers right now. If it only costs Wilken and some international bonus pool money or a DSL lottery ticket for Holmes sure do that trade but I think the Mets will be looking for something more. Detmers will probably cost the most but I think the Brewers could get him for something like Adams, Coleman Crow and a DSL lottery ticket.
Gausman is harder to gauge on if he will be available or not. The Blue Jays are not really out of it for a final AL Wild Card spot but they aren't really in it either. I think a similar package as what the Angels will be looking to get for Detmers will be close to what the Brewers will have to pay for him.
The trade market should pickup now that Skubal is gone. If I could get the Reds to part with Greene I would send over Pena in the deal but the supporting pieces would be less. The Mariners would make a good trading partner but I think they are looking for someone who could help them next year or this year so I don't think there is a fit there. Pena for one of their starters would work the best but I'm not sure the Mariners would be interested in that. Maybe this is where you could convince someone to take on Frelick something like Frelick, Adams and Crow for Kirby. I'm not sure if that is too much or not enough. I guess it depends on your valuation of Frelick and Adams and also of Kirby.