To make room for Robertson on the 40-man roster, right-hander Adrian Sampson was transferred to the 60-day disabled list as he recovers from a right flexor bundle strain.
The Mariners had been going with an extra reliever since sending Norichika Aoki down to Tacoma two weeks ago.
Robertson, 30, has hit .274 with 28 RBIs and six stolen bases in 107 Major League games.
Rollins has pitched in four games for Seattle over two stints with the big league club this season and has yet to allow a run in four innings.