Riley is replacing Cardinals third baseman Nolan Arenado, Anderson is replacing the Giants' Carlos Rodón, Cronenworth is replacing Marlins second baseman Jazz Chisholm Jr. and Espinal will replace Astros second baseman Jose Altuve.
Riley joins the roster in the midst of a hot streak that has seen his OPS surge to .913, third-best in the NL. He's second in the Senior Circuit with 26 home runs and sixth with 60 RBIs.
Cronenworth, who is an All-Star for the second time, has nine homers and 49 RBIs to go with a .261/.337/.394 slash line. With Chisholm, a fan-elected starter, inactive for Tuesday's Midsummer Classic, Mets second baseman Jeff McNeil has been moved to the starting lineup.
Anderson is 10-1 for the All-Star-host Dodgers with a 2.96 ERA, good for 12th in the NL, while his 1.02 WHIP ranks eighth. Espinal is enjoying a breakout season as the Blue Jays' main second baseman, batting .271/.322/.394 with 37 RBIs.