According to MLB.com, Rodriguez confirmed the waiver claim before Tuesday's game against Colorado. If a deal is not made between the clubs in 48 hours, the Astros must pull the left-hander off waivers and he'll remain on their roster.
Rodriguez, who is under contract through 2013 and has a player option for 2014 if he switches teams, has gone 9-9 with a 3.31 earned run average in 23 starts this season. He has won at least nine games in each of his seven big-league seasons, all of which have been in Houston.
The Rockies also activated Alex White from the 60-day disabled list to start Tuesday's game against Houston. White was one of four players acquired from Cleveland in the Ubaldo Jimenez trade last month.
To make room on the 40-man roster, the Rockies transferred pitcher Juan Nicasio to the 60-day disabled list, while also placing pitcher Edgmer Escalona on the 15-day disabled list with a right rotator cuff strain.