After the 1980 season, Strain was traded to the Cubs for Jerry Martin and Jesus Figueroa. Strain started the 1981 season as the Cubs second baseman, but his year in Chicago ended up with him being released on June 2, 1981.
One of the interesting tidbits about Strain is that he was in a punk-rock band with two other San Francisco players, and they were called the "Giants Prospects." John Tamargo was on drums, Greg Johnston on bass, and Strain on vocals and guitar. From what we can gather, they weren't very good ... just a good way to blow off some steam on the road in the minors. A copy of their band flyer is included below, made to depict a baseball card.
It's unclear what Strain did after being released in '81, but he returned to the Giants organization and became the manager of the short-season class A team in the Northwest League in Everett, Washington from 1984 to 1990.
Currently, Strain resides in Colorado and is the West Coast Scouting Supervisor for the Giants and had a lot to do with putting together the 2010 and 2012 World Championship teams. In fact, he was the scout that signed Sergio Romo!
Strain Running the Bases During Spring Training
The Punk Rock Band - "Giants Prospects"