Chiefs lock Tyler Ardron, who missed last week because of sickness, will start at blindside flanker as Hugh Blake's shoulder injury, which saw him leave the field after half an hour in Rotorua, has not come right.
The man who replaced Blake then, Zane Kapeli, will again come off the bench with McMillan hoping he can make as big an impression in Pukekohe as he did against Taranaki.
That means rookie locks Kane Le'aupepe and Aaron Carroll, who both scored tries in the season opener, are again paired in the second row.
The Steamers scrum was under real pressure in the first half against Taranaki until there was what McMillan calls a "technical adjustment" made at half time.
"Basically, the back five were not pushing hard enough. You have to be prepared to scrum for longer in this competition. You can't get the first two or three seconds right and then expect the last five or six to just unfold.
"We had some young fellas in there playing their first game and while they shone in some areas they learnt their lessons in others" he said.
The Steamers' best start to a season for three years has raised expectations, but McMillan is warning his players and fans not to get too carried away at this time.
"We've learnt over the years you can't dwell on wins and losses too much. Otherwise you get caught with your pants down.
"It's game one in a long competition and we have to get our feet back on the ground pretty quickly."
Because of the quick turnaround – just five days between matches – don't expect too much in the way the Steamers approach the game against the Steelers.
"We're not going to stray too much from what worked for us last week. Our guys operate well when they're really clear as to what their roles are and what we want to achieve as a team.
"We've only had two trainings since the first match and if you try to throw too much in you can get yourself in a tangle, so we try to avoid that."
That would suggest the Steamers will concentrate on their accuracy with the ball in hand, retaining possession and ensuring many multi-phase sequences.
Their dominance in that area against Taranaki is reflected on the statistics sheet. The Steamers completed 197 passes to Taranaki's 134 and carried the ball 96 times to the opposition's 35.
With the wily veteran Mike Delany guiding the team from first five-eighth in the absence of Polwart, the onus will be on Bay of Plenty to again avoid mistakes and turnovers.
McMillan knows what could happen if they cough the ball up.
"We need to be alert at all times. They've got some pretty electric backs and big hard ball carrying forwards and they'll run from anywhere."
The match starts at 7.35pm tomorrow at Pukekohe.