Both of the summer signings have struggled for match fitness at Bramall Lane.
Injury-hit Clarke has not featured since a substitute’s appearance at AFC Wimbledon on September 10 due to ankle surgery, while Canadian Lavery - a summer arrival from neighbours Sheffield Wednesday - is yet to start a game.
Yet the Blades sit eighth in League One, with a game in hand on all the teams above them, after having a blank weekend due to the international break.
“It was a good break, and we have tried to get the full benefit out of it - both players and staff - because it’s been a hectic start to the season,” said Wilder.
“Players have trained extremely hard. Lavery is fit, (Stefan) Scougall got a bang, a couple of others have had bumps and bruises they have been carrying for a couple of weeks, so they have all cleared up.
“Apart from Leon, we have a full quota to pick from on Saturday.
“The players are raring to go for the next game, against a decent team who have a good points total so far.
“Leon is not a million miles off, he has been walking about in this boot.”
Eighteen points from 11 games - including their current run of seven matches unbeaten - is a decent return for Wilder’s new-look team, although they have had to rely mainly on Billy Sharp and Matt Done for goals from their forward line.
Wilder has some sympathy for Clarke, the 31-year-old striker who has netted once - against Crewe in the League Cup - since moving from Bury in the summer.
Wilder said: “It’s been a difficult period for Leon, he came here as a big striker for us - in name and stature - and he was expected to be in and around the first team.
“I think it just goes to show how well the boys at the top of the pitch have done, carried on picking up points without Leon.
“When Leon is back, and Lavery, that certainly strengthens the top of the pitch for us.
“We hope Leon will be back at the back end of this month, or certainly going into November he will be fit and raring to go.
“He’s working extremely hard, and his recovery is going well.”