McMillan (knee) did not participate at the Buccaneers' practice Thursday, Scott Smith of the Buccaneers' official site reports.
The Bills placed Flannigan-Fowles (undisclosed) on injured reserve Thursday.
Gardner-Johnson (calf) was a full participant in Thursday's training camp session, Alaina Getzenberg of ESPN.com reports.
Egbuka (lower body) will participate in Thursday's practice, Scott Smith of the Buccaneers' official site reports.
VanSumeren (knee) participated in Buffalo's training camp Wednesday, Matt Parrino of Syracuse.com reports.
Coach Todd Bowles said Egbuka didn't practice Tuesday due to soreness in his lower body, Brianna Dix of the Buccaneers' official site reports.
McMillan (calf) isn't practicing Tuesday, Jenna Laine of ESPN.com reports.
Johnson sustained a strained groin during practice Tuesday, Scott Smith of the Buccaneers' official site reports.
McMillan didn't practice Monday or Tuesday after banging a knee "a couple days ago," Scott Smith of the Buccaneers' official site reports.