The New York Yankees won on Opening Day at Yankee Stadium on Monday, but what they lost could be tough to overcome, as closer David Robertson was placed on the DL and that means he will be out for at least two weeks and it forced Shawn Kelly to step in to earn the save against the Baltimore Orioles.

The Yankees had the near-impossible task of replacing Mariano Rivera coming into this season and while he is no Mo, Robertson was a great candidate to have in the bullpen, but now the team will have to stitch things together for at least a couple weeks. According to ESPN.com, Robertson will hit the DL after coming down with a groin strain and now the Yankees may have to deal with the closer by committee for a little bit of time until Robertson can return.

The injury happened in Toronto on Sunday and came when Robertson was pitching in the ninth inning of the win against the Blue Jays and after undergoing an MRI, it was shown that he had a Grade 1 strain, which is not serious, but it will keep him out for at least two weeks.

Robertson was an ideal choice to replace Rivera after two decades with the Yankees, as he has an excellent fastball that can be difficult for hitters to pick up and at his age he could take over the role for the long-term. Robertson previously had some closing experience a couple years ago when Rivera was lost for the season with a knee injury, but he eventually lost that to Rafael Soriano after he hit the DL himself and by the time he came back, Soriano had taken hold of the closer's role.

Robertson has shown he can be an elite relief pitcher, as he had a 1.08 ERA in 2011 and also had 100 strikeouts in 66 innings and he was basically unhittable while setting up for Rivera. Robertson said to reporters after the game that he has never had a hamstring injury before and he didn't seem worried about coming back when the two weeks were up. ESPN.com reports that the Yankees will use a Adam Warren, David Phelps and rookie Dellin Betances until Robertson can return and this comes after the closer started the season with two saves in three innings pitched.

"It kinda cost me a little command but I grinded through it," Robertson said. "But I think I can be back in 15 days."

Mark Teixeira injured his hamstring and he will hit the DL as well.