The Chicago White Sox started their “Black Friday” shopping a little early, signing former Detroit Tigers catcher Alex Avila on Wednesday to a one-year contract. (Thanksgiving dinner yesterday at the Avila household must have been a little awkward as Al Avila, father of Alex, is the General Manager up in Motown.) Now that a platoon partner has been found for Tyler Flowers behind the plate, the White Sox can focus on the rest of their shopping list on Friday: a third baseman, a right-handed starter to plug in behind staff ace Chris Sale, infield depth, and a new designated hitter.