The England under-21 international is back at The Hawthorns following a successful loan spell with Bolton Wanderers.
Clarke expects him to play some part between now and the end of the season.
"Craig is back, he loved his time at Bolton and got great experience," Clarke told the Birmingham Mail.
"He just got experience and minutes on the pitch and he feels he's come back in a good place.
"He's enjoyed his experience of playing. It was a good loan because it worked really well for Craig and for Bolton because when he went there their season seemed to turn a little bit.
"It worked out well for everybody. Dougie has players that can go in his place, good, experienced players.
"The team now are on a good, upward curve and if they get a good result at the weekend they will be in the play-offs and we can all sit back, relax and enjoy the play-offs."