It will not be any of the three players' first stint with the team this year, but each one probably has more to prove now than they did when they first came up. Zach Stewart, for instance, looked for all the world like a hopeless case when he made his start against the Angels. Los Angeles would put up nine runs on the young starter in just three innings of work--one of the worst outings that the Sox have seen from a starting pitcher all year.
Pedro Beato doesn't even have three innings to his name with the Sox, but arguably deserves more leeway. Allowing two runs in two innings isn't good, but the runs came after he had already picked up his six outs, as Bobby tried to stretch him into a third inning of work. That's a pretty tough situation to be in for a guy who has been nothing but a short order reliever for three years now.
Danny Valencia, on the other hand, is what he is: a backup infielder with little bat. Perhaps his presence will keep Mike Aviles and Mauro Gomez away from third in case of an emergency? Aviles had a rough go of things there yesterday, and Gomez...well, that's always an adventure.
Since all three players were already on the 40-man, no counter-move will be necessary.