I would recommend going to the bars on O St. after the game. Depending on your age and what kind of environment you're looking for, I can give you some recommendations. For example, bars like the Brass Rail, Hours, and Iguana's Pub tend to grab the youngest, more party-focused drinkers (i.e. fresh off the bus 21-year-olds). Bars like The Watering Hole, Duffy's and Barrymore's tend to have the more relaxed drinkers just looking to hang out and drink. Not to say those bars aren't fun, but a place like Hours is definitely like a dance club.
Now, I don't rightfully know exactly what the bars are like right after Husker games, because I only turned 21 on November 30th of last year, days after the last home game against Colorado. I'm just going off of my experiences when I've gone down there on regular Friday or Saturday nights.
Also, Lazlo's is one of my favorite restaurants and there's one in the Haymarket. Furthermore, there is a Brewsky's Sports Bar down in the Haymarket which might be worth considering.