If the Cardinals add three new starting pitchers, who is the true number one?

John Mozeliak is set out to control the pitching free agent market this off-season. It is unclear if he is simply filling voided areas or if he is going into the off-season with a depth chart in mind.
Championship Series - Arizona Diamondbacks v Philadelphia Phillies - Game Two
Championship Series - Arizona Diamondbacks v Philadelphia Phillies - Game Two / Sarah Stier/GettyImages

The St. Louis Cardinals are preparing for an overhaul this off-season to fix the imploded pitching staff. The DeWitt family is ready to spend money to save their brand image from an atrocious lost season of 2023. It has been speculated that the Cardinals are looking to add three starting pitchers, names including Sonny Gray, Aaron Nola, Yoshinobu Yamamoto, and Jordan Montgomery.  Let's say John Mozeliak wins the offseason and signs at least three of the pitchers listed above. That leaves a potential rotation of Gray, Nola, Yamamoto, Montgomery, and Mikolas (maybe Steven Matz). Knowing the overhaul that is expected, who are the Cardinals wanting to make their true number one heading into a postseason series?

Sonny Gray had the best 2023 season which will drive his market value up. He put up a 5.3 WAR tossing 184 IP with a 2.79 ERA. He looked really good all season for the Twins and has not pitched this much in a season since 2015. Gray has always been consistent, but his durability and age will be in question.

Aaron Nola has been as durable as they come. His career 162-game average for IP is 206 which is almost unheard of in today's game. A true ace has to be reliable and Nola can offer that by showing up to the field every 5th day. The problem with Nola is consistency though. He had a mediocre season in 2023 where he had a WAR of 2.1, an ERA of 4.46, FIP of 4.03, and a WHIP of 1.151. He pitches like a rollercoaster throughout his career and continues to do so.

Yamamoto is an intriguing choice. He looked dominant in the 2023 WBC and pitched very well in Japan this season. He pitched 171 innings with a 1.42 ERA and 0.860 WHIP. Will it translate well to MLB? Roll the dice and find out. He is 26 years old and can be the face of the staff for years to come.

Jordan Montgomery continues to increase his value heading into the 2023 off-season. He has looked really strong in Texas and is performing on the game's biggest stages in the postseason. He would be a great addition to return to St. Louis but the price might be too high to meet it. 

Lots of options to decide on. Who do you think will be the future ace of the St. Louis Cardinals?