For all those people that want to trade Girardi, let me ask you this. Who is going to replace his minutes on the right side?
Stralman is a fine 2nd pair defenseman. Allen and McIlrath are 3rd pair defenseman at best right now, and almost certainly not 1st pair RHD. If Girardi is traded, the team is missing a 1st pair RHD. You can't just bump everyone up a pair or sign some average RHD to play the minutes that Girardi did and expect that you won't have problems. McDonagh can cover others mistakes, but he can't handle an entire top line from a team like Washington or Pittsburgh by himself.
The Rangers are bereft of RHD on the team and in the system. They need to keep Girardi and sign him to a contract. The only way that it would be fine if they traded Girardi was if they got a potential 1st pair RHD back in the trade for him or drafted one this year. Seeing as that doesn't seem likely given his lack of star value on the trade market and the Rangers probable drafting position, trading Girardi should and is not an option. They also can't afford to let him walk in free agency. He is the most important piece in the organization besides McDonagh, IMO. Its just not easy to find guys that are first pair defenseman. You can find a forward who could be a potential 60 point guy in the later rounds. In fact, the Rangers found two forwards that look like potential 50-60 point guys 5 picks apart in the third round of the 2013 draft. Finding a 1st pair RHD is extremely hard, and I think the Rangers would be wise to keep their 1st pair RHD and sign him.
If the team is going to tank and not care about weaknesses, then trade Girardi along with Nash, Callahan, Lundqvist and Staal, but as long as the Rangers are aiming to win the Cup with this group, Girardi is not an option to trade. He can't be replaced easily.