Welcome back to our latest subscriber mailbag. With rosters expanding and the postseason looming, the Los Angeles Dodgers know it’s time to step it up.We broke down what the playoff rotation could look like, along with the plans for Will Smith’s impending return in Part 1 of the mailbag. This time, we’ll discuss whose performances will matter most this month as the back-to-back champs try to lock down their best 26 players come October.Without further ado …(Some questions may have been edited for length and clarity.)Which Dodgers heading into September are on the bubble and competing for postseason roster spots? — SoCal B.It’s hard to say now. The health of players like Andy Pages and Dalton Rushing will impact decisions. And while Edwin Díaz, Kyle Tucker and Teoscar Hernández aren’t in danger of being left off the roster, their roles in October could change if they don’t show improvement in September. That would impact the postseason roster construction.Let’s assume the Dodgers carry the typical 14 pitchers, including Ohtani and 12 position players (though as we saw last postseason, that wasn’t always the case). If the Dodgers are all full strength on the final day of the season, expect Rushing and Hunter Feduccia to make up the left-handed side of the reserves. Expect Feduccia to remain the backup catcher while Rushing serves as a bench bat as he attempts to play through a minor UCL tear. The right side is for trusted veterans Miguel Rojas and Kiké Hernández, bench players for most of the season but essential to the team in October. President of baseball operations Andrew Friedman and manager Dave Roberts value familiarity and experience (and the veterans’ performances in Games 6 and 7 of the World Series show why).