Out in the Nationals bullpen, just like everyone else in Nationals Park, where it was 41 degrees at first pitch, they could feel the chill. “I couldn’t really feel my toes out there,” Tyler Clippard said.

The relievers had to start warming up earlier than usual, but not only because of the weather. Every bullpen needs time to sort out its roles, who pitches in what circumstances. For the Nationals bullpen, without a clear-cut closer at the top, that’s especially true.

For opening day, the ambiguity did not bother the bullpen. Todd Coffey, Tyler Clippard and Sean Burnett faced the minimum after Doug Slaten walked the only batter he faced. It’s just one game, but Nationals relievers served notice they won’t let the current lack of defined roles affect them.

“I don’t think you should,” Clippard said. “I know for me personally, it doesn’t. I think we’re all on the same page. This year, we’ve gotten together and we’re working as a unit down there. Whichever situation any of us pitch in, we’re getting outs. That’s the bottom line. Whenever Jim calls down and calls whoever, that’s just how it goes. It shouldn’t affect any of us.”

The Nationals’ bullpen was their biggest asset last season, posting a 3.33 ERA while pitching more innings than any in baseball. This season, they entered without a firm closer. Today offered a possible clue that Sean Burnett would be the man who gets the first crack.

Down 2-0 in the ninth, Burnett entered and shut down the Braves in order, recovering from a leadoff single up the middle with a 1-6-3 double play and a strikeout of Dan Uggla. Typically, Manager Jim Riggleman would only use his closer when ahead or tied in the ninth. But since the Nationals had a day off yesterday and will have another one tomorrow, he chose to keep Burnett fresh, not Drew Storen, the other leading closer candidate.

“If you’re tied in the ninth, that would be a situation for a closer,” Riggleman said. “When you’re down in the game, not so much. But with no game yesterday, no game tomorrow, we felt like it might be a good day for Burnie to get the edge off a little bit and keep this game as close as possible.”