Giants experiment with Umenyiora, Robbins on second unit

EAST RUTHERFORD, N.J. -- The struggling New York Giants continue to tinker with their defensive lineup, demoting longtime starting defensive end Osi Umenyiora and starting tackle Fred Robbins to the second unit during practice.

Mathias Kiwanuka replaced Umenyiora and Chris Canty took Robbins' place on the first unit during practice Friday.

• Sunday: Cowboys at Giants, 4:15 p.m. ET

New York has lost five of its past six games and is hoping to salvage its season going into a key NFC East matchup at home against Dallas.

If the changes remain in place Sunday, it will mark the first time since 2004 that former Pro Bowl selection Umenyiora did not start when healthy and the first time since 2007 that Robbins was a reserve.