The Astros keep on winning.
Lyons has served as a spot starter and long reliever for the Cardinals at various points over the last two seasons.
Colvin opted out of his minor league deal with the Marlins at the end of spring training after failing to make the Opening Day roster and spent a month looking for a new gig.
That was the first career grand slam for Plouffe.
Varvaro was designated for assignment by Boston on April 29 after struggling badly in three straight relief appearances.