Playoff baseball is well underway, and college teams are keeping a close watch on the action and their former players now playing on baseball’s biggest stage.

Cal State Fullerton has the most alumni on playoff rosters this year with five. The Titans also last year led all colleges with five players on postseason rosters and this year tied for the most players on Opening Day rosters with 10.

Fullerton has two players in the World Series - Nationals catcher Kurt Suzuki and Astros reliever Chris Devenski, who was added to the roster before the Fall Classic. Athletics third baseman Matt Chapman and outfielder Khris Davis and Dodgers third baseman Justin Turner all also appeared on playoff rosters.

Florida had Cardinals outfielder Harrison Bader and Braves righthander Darren O'Day going head-to-head in the other NLDS, while Athletics lefthander A.J. Puk and Rays catcher Mike Zunino were on opposite sides of the AL Wild Card Game.

LSU's postseason contingent includes Astros third baseman Alex Bregman, Astros righthander Will Harris, Yankees second baseman DJ LeMahieu and Nationals outfielder Andrew Stevenson. Stevenson is not on the active roster for the World Series.

Louisville was represented by Braves outfielder Adam Duvall, Yankees righthander Chad Green, Rays lefthander/first baseman Brendan McKay and Dodgers catcher Will Smith.

Chipola (Fla.) JC, Old Dominion and Virginia rank fifth with three alumni in the postseason. Fourteen schools have two former players on playoff rosters.

In the World Series matchup between the Astros and Nationals, Fullerton (Devenski and Suzuki), LSU (Bregman and Harris), Old Dominion (Daniel Hudson, Nationals and Justin Verlander, Astros) and Virginia (Sean Doolittle, Nationals and Ryan Zimmerman, Nationals) all have two former players in action. Twenty-one colleges are represented in the series.

Of the 263 players on playoff rosters this year, 130 went to a two- or four-year colleges. They represent 97 different schools, from Akron (Chris Bassitt, Athletics) to Young Harris (Ga.) JC (Nick Markakis, Braves).

This count credits players for their final college season before they went to pro ball. Players who went to a four-year school after junior college are counted only for their four-year school.

(Totals updated following additions made before the World Series)

College Baseball Players In MLB Postseason