Luck is what happens when preparation meets opportunity, so the old saying goes.  Someone on the Kentucky bench may be about to get some “luck” when it comes to playing time.Unfortunately, it could be the result of bad luck for Darius Miller, who suffered a leg injury in the second half of Saturday’s 81-77 loss at Vanderbilt. If Miller can’t go, head coach John Calipari said after the game it would mean more minutes for sophomore Jon Hood. If Hood doesn’t step up to meet that challenge, then perhaps someone else on the bench could get their chance.Coming off the bench is a difficult role. As Calipari has said, if the score goes the wrong way for Kentucky, then the sub isn’t going to last long on the court.  Maybe that player who gets pulled out would have turned it around on subsequent plays, but most coaches aren’t going to wait to find out when they have someone else that is proven sitting on the sidelines. It’s just the dilemma faced by players who have not demonstrated enough in practice or games to warrant the longer leash from the coach.However, when a thin team gets an injury, that mindset can change and the head coach will have to forgive a mistake or two more readily when he doesn’t have that other option sitting next to him.That’s what happened in 1997 when Cameron Mills seized his opportunity to move from mop-up minutes to playing long stretches when the game’s outcome was in doubt.In a mid-January game at Rupp Arena, senior star Derek Anderson suffered a season-ending knee injury and Mills soon found himself getting the call to enter the game much earlier than usual.”All of a sudden, because there’s no other two guard, coach (Rick) Pitino had to give me playing time,” Mills said last week in an appearance on the “The Leach Report” radio show. “(Until then) I was halfway through my  junior season and I was still the guy who would come in at the end of the game when we were up 30 or 40.”   In the first game after Anderson’s injury, a matchup with Vanderbilt at Cincinnati’s Riverfront Coliseum, Mills wasn’t expecting to be summoned so soon and his stint was a short one. He missed three shots in three minutes, committed a foul and returned to the bench.   For a walk-on player, that might have his one-and-done chance at meaningful minutes, but being short-handed meant the coach called on him early again in the next game for a Super Bowl contest at Arkansas.   This time, Mills was ready.Mills played 16 minutes and hit 4-of-5 shots en route to a career-best 12 points as the Wildcats got the win in Fayetteville, Ark., 83-73.”He puts me in the Vandy game in the middle of the first half and it blew my mind,” Mills said. “I wasn’t ready for that. All of a sudden, middle of the first half, they say, ‘Cameron, go,’ and I’m like ‘Go where?  Locker room?’ But in the next game, I was ready. That Arkansas game, I knew I could shoot, so when I was open, I shot and they just started falling. But I was doing more than shooting. I played some good defense – relatively good for me. I even made a 3-point play the old-fashioned way, which is maybe the only time in my career I did that.”Before that day at Arkansas, Mills had played in 25 games in two-and-a-half seasons for a total of 48 minutes, scoring just 31 points. For the remainder of his career, Mills played in 59 games and scored 334 points, including a huge 3-point shot to tie the game against Duke late in the 1998 South Regional final.Had Anderson not been injured, Mills’ role might never have changed. Coaches don’t like to “take a chance” and risk a loss with an unproven player — unless they are out of options.   That situation led to Mills’ opportunity to play through his jitters, inexperience or whatever you want to term it. There was no guarantee for the Cats that he was going to make the most of his chance, but to his credit, that’s what he did.  This week, a current Cat or two might get that same kind of opportunity but it will be up to them to be prepared to seize it. If they do, the payoff can be sweet.Mills became a key bench player on teams that played in back-to-back national title games, winning it all in ’98.  Still, he most remembers that breakout game at Arkansas.”We’re on the plane on the way home and I’m sitting in the front,” Mills said. “We’re getting ready to takeoff and Delray Brooks shouts at me from the back of the plane, ‘Hey Cam, great game,’ and that was so cool. Coach Pitino made a big point after the game of congratulating me. After the game, we fly into town and I immediately drove home to see mom and dad and I said, ‘How about that?’ “