For whatever reason, sometimes I am only able to find one card of certain players. To be considered a One-Card Wonder, a player must have been active since 1991 (when I started paying attention).
There are actually parallels of this card and there is also an earlier card in the 2006 Upper Deck set that has a Red Sox logo, but Riske is shown in an Indians uniform. This is the only card I have so far of Riske in my Red Sox collections though.
David Riske was acquired in the same trade with the Indians that brought Coco Crisp to Boston. He was a right-handed middle reliever with some decent stuff. He made it into eight games with the Red Sox and was 0-1 with a 3.72 ERA in 9.2 innings with five strikeouts and three walks. Okay numbers for a middle reliever.
In June Riske was sent to the White Sox for side-arm-throwing southpaw Javier Lopez, who was a big part of Boston's bullpen for a few years. Riske continued to pitch well for the White Sox in 2006 and followed that up with a very good season for the Royals in 2007. He then went to Milwaukee for a few years.
EDIT: I have recently added another Riske card. He no longer qualifies as a one-card wonder.