Wallace was the match-winner as Sheffield Wednesday secured a fourth-straight win on Tuesday.
Bannan sat out the Owls' last three Championship matches, having been shown a straight red card in last month's 3-0 win at Nottingham Forest.
The 26-year-old was in sparkling form prior to that, earning him a recall to Gordon Strachan's Scotland team after a year away.
Celta Vigo loanee Alex Lopez started the last two matches in Bannan's absence and was instrumental in the 3-0 win against Charlton Athletic beforehand, having featured as a half-time substitute.
And Wallace has been impressed with the Spaniard.
"We lost Baz [Bannan] for three games and we were disappointed with that with the way he was playing," Wallace told the Star.
"Alex Lopez has just slotted in there and it has been like he has been in midfield all season. He has been fantastic in the last three games. He is a good technical player and has a great range of passing.
"The manager has got a headache whether he’s going to keep the same team or change it and bring people back in."
Wallace has activated a year's option on his Hillsborough contract, which was due to expire this summer.
The 30-year-old has been a regular for the Owls since his free transfer from Burnley last summer, and scored his fourth goal of the campaign in Tuesday's 2-1 win against Blackburn.
Wednesday's equaliser also owed much to Wallace, who saw his cross loop in off the foot of Rovers defender Adam Henley.