Whenever someone has to step into the shoes of a legend and attempt to fill in for him, it's always going to be a challenge—especially when it is someone with the degree that Mariano Rivera brought to the New York Yankees. The Yankees' current closer situation, in particular, is going to be put under a microscope almost as much as the battle for shortstop will once Derek Jeter decides to call it quits.
However, even after all that, David Robertson is there to fill a hole vital to New York's playoff hopes. Moving forward, he should be the X-factor and will be key in determining just how successful this year's team can be.
He's not the only one, though. There are players all around the league looking to improve their team's playoff chances. Here are the 10 that stuck out the most.