Clay Buchholz is back throwing, at least. The Red Sox right-hander, who’s only made two starts in the last month-plus, played catch before Tuesday’s interleague series opener against the San Diego Padres at Fenway. Manager John Farrell said Buchholz’s return to throwing -- his first foray since discovering bursitis in his right shoulder during an MRI taken last week -- went off without issue. Buchholz threw from 60 feet prior to Red Sox batting practice on what Farrell said is the first day of a mapped-out process. “The throwing program will be outlined to 60, 90, 120 feet, [with a] varying number of throws or a progressive number of throws before we get him on the mound,” Farrell said after Buchholz’s session.