Quintana signed a one-year, $2 million contract with the Pirates on Sunday, Robert Murray of FanSided.com reports.
The left-hander struggled with a 6.43 ERA and 1.73 WHIP in 29 games (10 starts) between the Angels and Giants last season. Quintana has thrown only 73 innings over the last two years, so it remains to be seen whether he can stay healthy and pitch well enough to be a back-end rotation option for Pittsburgh.