The Indianapolis Colts opened up their preseason slate Sunday afternoon against the Detroit Lions. They did so without franchise quarterback Andrew Luck, who remains sidelined following offseason shoulder surgery. 

While Luck has been throwing on the side, he's yet to participate in practice. This has led to speculation that the former Pro Bowler might miss the start of the season. In fact, some believe Luck might be placed on the physically unable to perform (PUP) list to start the year. That would cost him the first six games. 

Owner Jim Irsay stopped short of that on Sunday, but did admit that there's a chance Luck could miss the first couple games of the regular season. 

With Luck sidelined, veteran backup Scott Tolzien started under center Sunday. In what can't be a major surprise, he was less than effective, completing 2-of-5 passes for 24 yards. 

Despite dealing with injuries, Luck has finished each of his past three full seasons as a top-four fantasy quarterback. This is most defintely something to keep an eye on as late-summer drafts are conducted. For now, we don't value him as much more than a bottom-end QB1 option in 12-team leagues.