DL help

I've run out of bench spots (used them all for offense) and noticed Osi Umenyiora is out for this week.  Would it be alright to drop him and pick up Mathias Kiwanuka to replace him.  My other DLs are Justin Smith and Shaun Smith.  Also available are Luis Castillo, Antonio Smith, & Shaun Ellis.  Or should I be looking to keep Osi Umenyiora season.

Sorry new to IDP. Any help would be appreciated.

I would pick up Kiwanuka if he's classified as a DL. He will be playing linebacker in base packages and sliding down to end in passing situations. So essentially your getting an every down linebacker at DE.