INDIANAPOLIS (AP) âÄî Tony Dungy doesnâÄôt doubt Bob Sanders will be back in the Colts lineup this season. HeâÄôs just not sure how long Sanders will be out. The 2007 defensive player of the year could miss up to six weeks after spraining his right ankle last weekend at Minnesota, and team officials are contemplating whether Sanders may need arthroscopic surgery on his knee, too. âÄúItâÄôs kind of similar to (receiver) Roy HallâÄôs injury,âÄù Dungy said. âÄúHe had his knee scoped, too, so heâÄôs going to be out a while longer. If itâÄôs going to be two or three weeks, then it makes sense to get it scoped. But (defensive tackle) Keyunta Dawson had the same kind of thing and he told me he was going to practice today, so weâÄôre not really sure.âÄù Apparently, those plans changed, too. Dawson did not practice Wednesday. Team president Bill Polian was more definitive Tuesday night while taping a segment for his Saturday night television show on WISH-TV. Polian said Sanders would miss four to six weeks. Dungy has been wary of establishing ironclad timetables since he told reporters that tight end Dallas Clark was expected to go on injured reserve after tearing his ACL during the 2006 season. Two days later, the prognosis changed and while Clark missed four games, he played in the season finale and had a prominent role in the ColtsâÄô Super Bowl run. The latest injury continues a strange even-numbered-year hex for Sanders, who played in just six games during his rookie season in 2004 and four games in 2006. In odd-numbered years, Sanders has started 14 and 15 games, respectively. Dungy wasnâÄôt even sure how Sanders was hurt at Minnesota. He left during the fourth quarter and hasnâÄôt been available to reporters since then. âÄúIâÄôm still learning the extent of it myself,âÄù Dungy said. âÄúI guess, whether it was the âÄòdreaded high ankle sprain,âÄô I guess I found that out Monday night.âÄù Losing one of the NFLâÄôs hardest hitters will certainly impact the ColtsâÄô struggling run defense. Indy has already allowed Chicago rookie Matt Forte and Minnesota Pro Bowler Adrian Peterson to each rush for more than 100 yards, and the Colts rank 28th in the league against the run. The likely replacement is second-year safety Melvin Bullitt, who made the team last year as an undrafted free agent. Bullitt finished with two tackles Sunday, but has often practiced with the starters.