Setting aside the speculation that is running rampant about what may or may not have happened to get Dezmine Wells dismissed from not only the team but also the school, his expulsion leaves Xavier in a very sticky situation as far as roster construction goes. Wells was going to be unquestionably the most reliable perimeter threat on a team stocked with a bevy of 6'7" to 6'10" interior players (now including Chris Cantino). Wells' explosive athletic ability was on display last season, and his jump shot was reliable enough to make him a threat on the outside, as well. Now he's gone, and there's a corresponding hole left for X.
The remaining guards on the team - and there are four of them - each come with their own question marks that Wells' presence would have nicely spackled over. Beginning with the most experienced, Brad Redford is a superb shooter whose range is only matched by the quickness of his release. He has no compunction about lifting from anywhere at any point in the game, and he has hit some huge threes for Xavier. Coming off of knee surgery, though, and being born with certain athletic limitations, Redford is a fairly limited player. His effort on the defensive end can't be questioned, and his ability to score after a dribble has improved, but he's still probably not a complete enough player to be sent out onto the court for long stretches of game time.
Dee Davis is, in many ways, the antithesis of Redford. His release is slower and his range is not nearly so vast, but he has wonderful quickness and ball-handling skills. Davis is also a dogged defender, getting into a ball-handler's personal space and daring him to do something about it. He is more than willing to put his slight body on the line for the team, but he is more effective as a change of pace guard and distributor than a primary option.
Semaj Christon and Myles Davis are - despite their well-deserved status as highly-touted prospects - relatively unknown quantities. Christon has earned praise for his athleticism and ability to score the basketball, while Davis is a knockdown shooter with range out to the parking lot. Both players might be able to play right away, or they might have an adjustment period at the collegiate level. It's very difficult to predict how a player is going to fare in the transition from high school to college.
What is certain is that all four of those players will get a shot - and likely multiple shots - to fill the new vacancy. Justin Martin will also get an opportunity to step up and fulfill the role of someone who can score the ball from the outside. While Cantino fills Wells' roster spot, there's absolutely no evidence he is a perimeter scorer. There's no doubt that all of those players have the talent to make a difference at this level, but Wells' departure leaves an already largely unproven squad frightfully thin.