One Patriot who has flown under the radar with NFL free agency set to begin on Tuesday is offensive lineman Donald Thomas. A league source said on Wednesday that the Patriots have shown interest in re-signing Thomas, but it is “fully expected” that he will test the market. The 27-year-old Thomas, who is a Connecticut native, played in all 16 regular-season games as well as New England’s two playoff games last season. He started seven games, all but one at left guard. With Logan Mankins missing time because of leg injuries, Thomas stepped up in his absence and played well, particularly since Thomas said previously he didn’t much like being at left guard.