Whether this is a must win or not depends on how you view our chances to finish in the top 7 in league. If we are a 9th place team in league, we could afford to lose this if we beat them on the 20th in a home game. If we lose both to GTown, we could be worse than a 9th place team. Win this one, beat Butler away, and at least for the moment our sights will be set higher than 9th. To look beyond the next 4 games (GTown twice, Creighton, Butler) is fruitless at this point. Needless to say, we will be feeling decently should we win the games that are more winnable (Gtown, Butler).
Reality is that 3-1 over the next 4 is most optimistic outlook, 2-2 realistic, 1-3 possible but we want to avoid that. A win today would go along way towards that end.