Mack (hamstring) was on the field for Monday's light workout, Zak Keefer of The Indianapolis Star reports.
Mack's participation shouldn't come as a surprise after he logged limited practices throughout last week before being ruled out for Thursday's eventual 38-24 loss to the Patriots. A return to full participation at some point in the coming days would put him on track to return for a Week 6 road game against the Jets. Mack doesn't offer much upside as part of a committee in a pass-heavy offense, but he might breathe some life into the pathetic Indianapolis running game.