Reds fourth-ranked prospect Cam Collier is expected to be promoted to Double-A Chattanooga, according to a source. Collier missed an extended period of time to open the season after he tore a ligament in his thumb during a spring training game against the Chicago Cubs. He underwent surgery in March. He made his return on May 19 with the ACL Reds and played in 10 games with them. He has played in 11 games with the Dayton Dragons in High-A. Collier is hitting .338 with eight extra-base hits in 21 games this season. Collier struggled in his rookie season before having a breakout season with Dayton last season and was named the Reds Minor League Position Player of the Year. The 20-year-old played