The playing surface at TCF Bank Stadium is "as hard as concrete" and "unplayable," according to tweets by Vikings punter Chris Kluwe. Minnesota had a brief practice at the field on Sunday. University of Minnesota officials have expressed confidence that the field would be in acceptable condition for Monday night's game despite a mad scramble to clear 20-inch snow drifts from the field this week. After Sunday's practice, Kluwe issued a series of tweets that predicted the game would be a "trainwreck." Via Twitter, Kluwe said he had been asked to stop tweeting about the playing conditions.