It's a minor issue and it's just a silly mistake on Miller's part. He's having a rough offseason and has been suspended by the league for four games for alleged marijuana usage and his appeal will be heard on Thursday. The 24-year-old pass rusher has 30 sacks in his first two years as a pro and is considered as one of the best at bringing down the quarterback.
Fantasy impact: There really is no impact from this particular offense, but the suspension in going to be a thorn in the side of the Broncos. Their schedule has some ups and downs. The ups start with the Raiders in Week 3. The Raiders may have the worst offense in the NFL and even without Miller, their D will be a must-start. They also get the Eagles and the turnover-prone Mike Vick.
Their schedule starts off a bit rough with the Ravens and traveling to New Jersey to face the Giants in Week 2. Those teams haven't been friendly to fantasy defenses and might not be worth starting. Although, at the early part of the season, fantasy owners probably won't want to use two roster spots on a defense. Most owners should be stashing as many high-upside handcuffs or possible breakout WRs. In other words, if you draft them, you might as well start them.
As for IDP owners, Miller will probably go a bit too high since he's a big name. Unless your league rewards for sacks in a major way, it's probably better to head in a different direction.