The Minnesota Twins activated second baseman Luis Rivas from the 15-day disabled list prior to Friday's interleague contest against San Diego. Rivas, who had been on the DL since June 1 with a left external oblique strain, was scheduled to make a rehab stint with Triple-A Rochester but instead started Friday for the injured Juan Castro. Rivas went 1-for-3 before leaving Friday's 5-4 win over San Diego for a pinch runner. In Thursday's 14-7 loss to San Francisco, Castro fouled a ball off his left ankle in the first inning and was forced to leave the game. X-rays were negative and he is listed as day-to-day. To make room for Rivas, the Twins placed infielder Brent Abernathy on the 15- day disabled list with a bruised right shoulder. The move is retroactive to June 15.