Here's a quote from the Denver Post...
Here's the link.
the Wednesday before the regular-season opener in Cincinnati, Mike Shanahan called McCaffrey, Lelie and Rod Smith into his office. He explained to each of them that he viewed them all as starters, but would change the lineup around a bit this season. Lelie started the opener, but McCaffrey still played more plays. So it's just an arrangement, more than anything else, although McCaffrey does have only one catch after two games.
One last time- Denver runs a very complicated offense. Perhaps one of the most complicated in the league, right up there with Oakland and Tampa Bay. After all, how many other teams in the NFL have a tackle with a receiving touchdown (and more receiving yards than their #3 WR, I might add)? So, with such a complicated offense, it stands to reason it will take time to learn. If you look at Plummer's performance against SD (which is, admittedly, weak against the pass), you will see that he was 9 of 13 for 97 yards and 3 TDs. That's almost 11 yards a completion, almost 7.5 yards per attempt, and a touchdown every 3 passes. Those are good numbers. Have faith that he will be able to achieve those numbers with a little bit more regularity later in the season once he finally gets all the pieces of Denver's offensive puzzle put together.
Until then, do not expect touchdown receptions from any Broncos who aren't Rod Smith, Shannon Sharp... or Carlisle Cooper