The Arizona Diamondbacks non-tendered starting pitcher Taijuan Walker and outfielder Steven Souza Jr. on Monday, making them both free agents. Walker missed most of the last two seasons after having Tommy John surgery, but he was able to post a 3.49 ERA in 157 1/3 innings in 2017. The right-hander will surely be coveted by teams looking for starting pitching help on the open market. Like Walker, Souza was injured in his two years with the Snakes, and he hit just .220 in 72 games in 2018 while...