3. Jordan Montgomery
Montgomery has clearly been the ace of the Cardinals pitching staff this year, and it's not even close. Montgomery has the second-highest WAR on the team behind Goldy, with a 2.4 WAR according to FanGraphs. Monty has posted a 3.28 ERA with a 1.238 WHIP, with only six wins to show for it.
The player I believe is closest to Jordan Montgomery in comparison is Josiah Gray of the Washington Nationals. Montgomery has a lower ERA, a lower WHIP, more innings pitched, and more strikeouts. This might be a case of every team getting an All-Star, and Josiah Gray being the best available player to include on the roster.
I firmly believe that Jordan Montgomery deserves an All-Star appearance, as he has been stellar since joining the Cardinals. I think that Monty's first All-Star appearance is more a question of when it will happen, rather than if it will happen, in the near future.