Ilunga has found himself frozen out at Upton Park after initially starting the season in Sam Allardyce’s first team.
However the Congolese international was notably left out of the side’s squad photo, a clear indication that he would be allowed to pursue first team football elsewhere.
The 29-year-old’s capture adds further Premier League experience to Saunders’ Rovers having completed the signing of Pascal Chimbonda on a short-term deal last week.
Doncaster have enjoyed somewhat of a revival under Saunders having picked up seven points out of a possible nine since succeeding Sean O’Driscoll in the hot seat.
A 2-1 win at Peterborough on Saturday lifted the side off the foot of the table and up to 20th place as they look to slay their pre-season tag of relegation favourites.