It appears likely there will be rain for much of the evening at Yankee Stadium tonight, which means that would would assume there's a decent possibility of tonight's game not getting played.
There's 100% chance of rain tomorrow, and 30% Sunday, which means that you have to be concerned that one of these games could end up getting rained out.
There's an off day on Monday for both teams, but that's the Rangers' only off day until May 10, a stretch of 20 games in 20 days the Rangers would have to play. My recollection of the rules is that the MLBPA requires the league to get the team's players' permission if there is going to exceed 20 straight days of games, and I have no idea whether the Rangers would agree to play on Monday, or just punt things off.
Given that the Rangers have a couple of starters on the d.l., one would think they might be motivated to postpone the game, but they won't be going back to New York again this season. I'm not sure if that impacts whether the Rangers would be forced to play on Monday.
Anyway, I'll see what I can find, and report back if I get any more info.