The third-round draft pick from Central Michigan started his first full game for the Colts at Denver over a week ago. He struggled to find his feet and committed four penalties for a total of 25 yards.
The Colts went on to win the game 12-9, but Raimann's underwhelming performance earned him a below 50 grade from Pro Football Focus.
"Right now I'd be willing to tell you we think he's going to be our left tackle," said Reich, via FOX 59.
"He did some good things (at Denver). I know there were some calls and some stuff, but that's just going to be part of the process.
"We feel he was a good pick. We feel he's got a lot of upside."
The 25-year-old rookie acknowledged that he has fallen short of the mark so far, but he believes with a few adjustments he should be providing QB Matt Ryan with better protection.
"Definitely had a rough start," Raimann said.
"I made a lot of mistakes, and there's a lot of things to learn from. Just things I really need to work on this week. In pass protection, just staying on my angle and not opening up too soon."
The Colts will host the Jaguars at Lucas Oil Stadium on Sunday, October 16.