With a free roster spot after last Saturday's release of Justin Miller,and Mr. "#75 had reported eligible" Robert Turner injured and out for the Bills game, the Jets had a free roster spot and no third tight end. To fill that roster spot, the Jets signed TE Matthew Mulligan from the practice squad.
Mulligan (6'4, 270) may or may not play tomorrow against Buffalo, but with the Jets only playing with two tight ends anyway - James Dearth doesn't count - it makes a lot of sense to call him up. Turner's injury might cause Mulligan to play right away. After all, the 24-year old has been learning the system since September 6th, when they initially claimed him off waivers from Tennessee.
It could also be a bad sign for blocking TE Ben Hartsock. His penalties got him called out by Rex Ryan a few weeks ago, and what good is a blocking tight end if he costs the team yards in penalties? He's been cleaner in recent weeks, but this has to push him even more.