Tournament officials said they hoped to play the second round Saturday and then have the survivors of the 36-hole cut play both the third and fourth rounds Sunday.
No rain is in the forecast for Saturday, but a chance of showers returns for Sunday.
Two-time U.S. Open champion Lee Janzen and Darron Stiles shared the lead after one round, both having fired a 7-under 64 at the TPC-Deere Run course.
Janzen has not won a tournament since he captured the second of his two U.S. Open crowns 11 years ago.
J.J. Henry, Matt Bettencourt and Dean Wilson shared third place at 65.
There have not been two rounds played on the final day of a PGA tournament since the 2005 International. This was also the first time a round had been suspended without any play since last year's BMW Championship.