The 6-foot-7, 320-pound rookie was signed by the Bucs as an undrafted free agent in April. He played in 49 college games at Mississippi and was a third-team All-SEC selection in 2010.
Indy is trying to solidify the offensive line after it gave up three sacks in a season-opening 41-21 loss at Chicago. Andrew Luck, the No. 1 draft pick, also was knocked to the ground numerous other times Sunday.
The Colts released two players from the active roster Monday to clear room for the addition of Sowell.