Reliever Mark Lowe, whose presence as the Seattle Mariners primary setup man has been missed since early May, will have back surgery to repair a herniated disc - and is almost certainly done for the season.
Lowe, 27, was credited by teammates and coaches last year for helping bring that group of pitchers together, and being the man who worked the eighth inning in so many games where closer David Aardsma got the ninth.
On the disabled list since May 3, Lowe's absence has been critical in Seattle's bullpen roles, forcing relievers to pitch in situations they previously hadn't dealt with successfully.
In 11 appearances this year, Lowe was 1-3 with a 3.48 earned run average. His surgery will be Tuesday.