Washington Nationals Manager Davey Johnson may have made up his mind on whether to keep either Chad Durbin or Ryan Mattheus as the last reliever, but he isn’t making it official until after today’s final exhibition game against Boston.

During a pregame news conference at Nationals Park, Johnson said as much when asked about that final roster spot heading into opening day, which comes Thursday at Wrigley Field against the Chicago Cubs.

“Basically we’ll go through today, make sure nothing happens,” he said. “But we’ve got a lot of good choices, so I’m not really concerned about it whichever way we go.”

Closer Drew Storen will start the season on the disabled list, and he threw a bullpen session before this afternoon’s game. That leaves a slot for Durbin or Mattheus, who is scheduled to pitch today.

Durbin, meantime, worked one inning on Monday in a spring training game against Boston in Lee County, Fla. He gave up two hits and one earned run and struck out two.

Both pitchers have fared well in spring training, but Durbin appears to provide more versatility, and his contract status may make him the more appealing choice.

Durbin is eligible to opt out of his minor league contract if he does not make the Nationals opening day roster. Mattheus, meantime, has a minor league option remaining.