2. Nick Castellanos
There isn't a hotter bat left in the MLB playoffs than Nick Castellanos... unless we want to mount an argument for one of his teammates. Casty went off in Games 3 and 4 of the NLDS, hitting two home runs in each game. He became the first player ever to get a multiple-base hit off a 100 MPH fastball from Spencer Strider. He is quite literally making history right now.
Castellanos doesn't have a great career record against Gallen (1-for-4 with a single, a walk, and a strikeout), but it hardly matters. He has momentum on his side, not to mention a rabid crowd hanging on every swing of his bat.
There has been a push to move Castellanos into the cleanup spot in place of the struggling Alec Bohm, but Rob Thomson is sticking with his guns for Game 1 of the NLCS. Castellanos will remain in the seven-spot. The urge to move Casty up is understandable — all four of his NLDS homers with solo shots, so it would be nice to get his hot bat in a position to knock more runs home. Still, there's equal risk in tinkering with the delicate balance of things. Castellanos is clearly comfortable with his current spot in the lineup. Plus, it's probably smart to avoid tainting Bohm's confidence.
Gallen will face the Phillies' early gauntlet (Scwarber, Turner, Harper, Bohm, Stott, Realmuto) before Castellanos steps to the plate. Coming off a productive second season with Philadelphia (.272/.311/.476 with 29 HR and 106 RBI), Casty might be the most intimidating No. 7 hitter in the league. He's definitely better than Kevin Pillar.