On Monday, MLSsoccer.com revealed its candidates for this season's 24 Under 24, their annual ranking of the league's best performing players under 24 years of age.

The Chicago Fire have four selections included among the 50-player shortlist - defenders Jonathan Campbell (aged 23), Brandon Vincent (22), and Rodrigo Ramos (21) as well as midfielder Matt Polster (23).

Polster makes his second appearance on the shortlist, having come in at No. 21 on the rankings during his 2015 rookie season. The U.S. Under-23 National teamer has seen his game evolve over the course of his sophomore campaign, having scored his first professional goal in a 2-2 July draw with the New York Red Bulls.

Rookies Vincent and Campbell - selected fourth and 12th in this year's MLS SuperDraft, respectively - have become mainstays among the Fire backline in their first years as professionals. Campbell has appeared in each of the Fire's 27 matches (25 starts) and is among the league leaders in defensive clearances (117), blocks (26), and interceptions (83). Vincent has featured 20 times this season, and represented the Fire in the 2016 MLS All-Star game in San Jose. Ramos has appeared 18 times for the Men In Red, with three assists to his credit as well as a Week 17 MLS Team of the Week selection for his efforts in a 1-0 victory over San Jose.

The Fire's four selections to the list were a league-high, level with FC Dallas, New York City FC, Orlando City SC, and Toronto FC. The top 24 players will be revealed starting on Monday, September 19, and were picked by a panel of soccer media members across the US and Canada. The cut-off date for eligibility for this year’s ranking was October 23, the final day of the 2016 MLS regular season.