Mid-way through the second quarter of Saturday's 55-14 victory over McNeese State, Roberson suffered an injury to his left hand that Snyder declined to disclose.
Snyder said the length of time would depend on Roberson's progress, but said, "There is no time, no day of the week being set when we might get him back. We just don't know that."
When asked if Roberson might miss the Big 12 opener on Oct. 4 at the University of Texas, Snyder said, "Yes, yeah ... could be. I don't know that for fact. We really don't know."
As for how the injury occurred, which was during an incomplete pass, Snyder would only say, "He just got hit."
Playing just five series, Roberson rushed for 37 yards and passed for 63 (3 of 6) in helping the Wildcats to a 3-0 start to the season.
For the year, the Heisman Trophy candidate has rushed for 251 yards, averaging 6.6 yards per carry and scoring four touchdowns.
Roberson has completed .447 percent of his passes for 502 yards and five touchdowns.
His place will be taken by Jeff Schwinn and/or Dylan Meier.
"They'll be getting more snaps, so consequently that should enhance their play," Snyder said. "It's hard to get three quarterbacks ready, so Jeff has taken far more snaps than Dylan has. Now, it will balance out."
Saturday, Schwinn was 5 for 14 passing for 83 yards, plus rushed for a net-seven yards in the third quarter.
"Jeff probably didn't handle himself as well as I know he is capable of," Snyder said. "He probably got a little anxious as much as anything."
Of his own play, Schwinn said, "I made some bad decisions and I was a little jittery out there in the pocket for some reason. I didn't do as well as I wanted to."
Playing the fourth quarter, Meier debuted by throwing an interception on his lone passing attempt, but later rushed for 46 yards, which included a 15-yard touchdown.
Schwinn is a 6-foot-2, 188-pound senior, while Meier, the younger brother of former KSU tight end Shad Meier, is a 6-4, 190-pound redshirt-freshman.
Already this season, K-State lost the services during the preseason of tight end Thomas Hill and defensive tackle Andrew Bulman for likely the entire season, plus running back Carlos Alsup, who last week suffered a season-ending knee injury.
In addition, junior college all-American linebacker Marvin Simmons has yet to see the playing field due to a hamstring injury.
Kansas State next plays the University of Massachusetts on Saturday in a 1:10 p.m. kickoff at KSU Stadium.
ELL ROBERSON OUT
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