Despite the second match of the series featuring at his home ground of Lord's, Finn has been widely tipped to be dropped from the team in favour of Tim Bresnan or Graham Onions, having taken just two wickets in the opening encounter.
However, Flower insists that those two dismissals were crucial for the hosts and played down talks of leaving him out of the side.
"Steven Finn took crucial wickets in that first innings," Flower said. "We only had just over 200 on the board in the first innings and he got Shane Watson early and then Ed Cowan first ball.
"Those were crucial breakthroughs for us. That sort of striking is one of the things he's capable of doing with his pace and bounce.
"He also bowled a really skilful spell of reverse swing against Michael Clarke and Steve Smith on the fourth afternoon, beautiful outswing and almost got an lbw with inswing. So he made his contribution to this game".
The second Test of the Ashes gets underway at Lord's on Thursday.