Descalso, 30, spent the last two seasons in Colorado. He hit .264 with a career-best eight home runs and 38 RBIs through 99 games in 2016.
The veteran infielder began his big league career in 2010 and spent five seasons in St. Louis, where he won a World Series in 2011.
Gosselin, 28, was acquired by Arizona in a trade with the Braves in June 2015. He's appeared in 146 games for the D-backs since, batting .283 with five homers and 26 RBIs.
Chad Thornburg is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.