Tom Saxton (ankle) and Jesse Joe Parker (compassionate leave) are unavailable for Featherstone in Thursday’s televised Co-operative Championship thriller.
Table-topping Rovers come head-to-head with second-placed Leigh knowing that victory will almost certainly secure the minor premiership.
Powell said: “We were a bit off with our skill level at Keighley. We made too many errors, particularly in the first-half.
“We’ll have to improve, and we know that. We’ve got to find ways of playing the game a bit quicker.”
He added: “We’ve got a couple of key individuals who’ll need to be better when we play Leigh, because they’re a good side.
“They’ll put us under pressure and they’ll be desperate to win because they’re slipping a little. We’ll need to improve, but I’m sure we will.”
Tommy Goulden returns to the Centurions team, less than three weeks after needing major facial surgery to repair a torn ear and ripped lip.
Leigh assistant coach Paul Rowley said: “We weren’t that good against Barrow on Saturday, but we could have still won the game.
“Even though our completion rate was probably the poorest it’s been all year, we still got a bonus point.
“We’re targeting a big improvement this week. Featherstone have been consistent all year, so if we go again with a low completion rate then they’ll punish us. They complete well, they’re very patient and very honest. We need to match them.”