1) Justin Verlander - New York Mets
Trea Turner is probably going to accumulate the most WAR over the totality of the contracts signed by each of the players who arrived in the NL East for the 2023 season, but Justin Verlander is the best player at least for right now who joined this insane division.
Verlander is coming off of arguably his best season on the mound in his Hall of Fame career. This comes after missing two seasons after undergoing Tommy John Surgery. The 39-year-old went 18-4 with a 1.75 ERA in 28 starts and 175 innings pitched. He won his third Cy Young Award and was the ace on a World Series-winning Houston Astros team.
In all likelihood, Verlander won't repeat the season he had. Again, he doesn't have to do that. If Verlander can give the Mets 25-30 ace-level starts and then give them big-time outings in the postseason, the big contract they gave him would be worth it.
The Mets signed Verlander to replace Jacob deGrom. While deGrom's talent is irreplaceable, his production certainly is. deGrom has given the Mets 26 starts over the past two seasons. Verlander surpassed that total last season.
While I don't expect another Cy Young season, I expect something similar to what Max Scherzer did last season. Scherzer was an ace for 90% of the season, and Verlander should be just as good as he was.