Herremans shifts from left guard to protecting Michael Vick's blind side. Herremans took the first-team reps at right tackle in Saturday's practice.
"They just think for now it's the best move for the team," Herremans said. "It felt good. Obviously, it's a little foreign. It's going to take some time, but in a couple of weeks I'll be ready to rock. I always felt like I could play tackle so now I just have to back it up now."
With Winston Justice on the PUP list, King Dunlap started the last two preseason games at right tackle. Justice, last year's starter at right tackle, is recovering from knee surgery.
The Eagles signed Ryan Harris, who started the first preseason game, to a one- year contract on August 2. Harris was the starting right tackle at one point, but he is having back surgery on Sunday.
Evan Mathis, who has 22 starts in 58 career games, will be the first-team left guard.
Maclin had been sidelined due to a Lymphoma scare. The Missouri product caught 70 passes for 964 yards and 10 touchdowns last year.
Smith agreed to terms on a one-year deal with the Eagles on August 10. The former Giant was recovering from knee surgery last December.
Maclin and Smith are now not eligible to be placed on the Physically Unable to Perform list to start the regular season since they practiced.
Both players hope to be ready for the season opener on September 11.