The most interesting of the three might be Garceau. The 28th ranked prospect in the Cardinals minor league system according to the Birdhouse, he pitched admirably as a 20-year-old in the Florida State League. Especially tough at Roger Dean Stadium, he posted a 4-1 record with a 1.69 ERA.
Brad Furnish was originally selected in the second round of the 2006 MLB First Year Player draft. Furnish struggled with consistency at Palm Beach before pitching well after a promotion to Double-A. The Cardinals rewarded him with a trip to the Arizona Fall League where he seemed to take a step back. The hitters in the AFL batted .323 against him contributing to his 7.47 ERA. Furnish struggled with his command as well, finishing with a 12-to-7 strikeout to groundball ratio.
Katsuhiko Maekawa was signed as a minor league free agent earlier this winter. Maekawa was signed after getting knocked around in the Venezuelan Winter League though the Cardinals scouts must have seen something in the 30-year-old.