According to Joe Strauss of the St. Louis Post-Dispatch, Cardinals outfielder Colby Rasmus requested a trade earlier this season. The decision was based off frustrations between the top prospect and manager Tony La Russa, despite both saying their relationship is fine.
Rasmus is hitting .264 with 19 home runs this season and a .349 on-base percentage, a big improvement from last season. However, he has only played in 117 games this season after playing in 147 last season. He was hitting .284 prior to the All-Star break but is hitting just .210 since.
Rasmus is a premier outfield prospect who certainly won't be traded this offseason unless it involves receiving a premier player in return. It is possible, though, that manager Tony La Russa will not be back next season.