In what is a huge boost for the Baggies, influential midfielder Mowatt was forced off with a suspected broken foot in the defeat at Stoke prior to the international break.
But scans have subsequently shown the injury isn’t as bad as first feared – with the 26-year-old in line to start tomorrow.
Centre-back Clarke – who began the season in fine form – could also return to the starting XI having not featured since injuring his hamstring during the win at Blackburn on August 21.
The Brighton loanee was fit enough for a place on the bench at Stoke.
But after coming through the international break unscathed, he is now ready to start.
Ismael, though, says he wants to be careful with the centre-back to ensure the Championship’s hectic schedule doesn’t lead to him picking up a similar injury in the future.
“For us it’s good news – it’s a relief for us that it’s not broken,” the Frenchman said when asked about Mowatt’s foot injury.
“It’s good for us that he has trained these last two days with the squad and he’s back in the squad.
“Normally, as long as something doesn’t happen and change overnight, he’ll be okay for the game.”
On Clarke, the boss said: “He’s back in training, back in the squad and trained very well.
“Now we need to manage him through these games.
“The Championship is ruthless. We play every three days, so we must learn from the first block with him and what happened to make sure that he can come through the games without another issue.
“He is fine, he is available, he trained well. We’re happy he’s back in the squad, but we need to find the balance and to manage him now.
“He’s very motivated, he wants to play, but we learn from the first block.
“He plays, plays, plays, he got cramp, we let him play and then he got the injury.
“This is what we’ve learned. We have very close communication.
“It’s all about making the right decision to make sure he stays with us all the journey.”
Another player Albion have available is Callum Robinson who was in prolific form during the international break.
The forward netted a brace for the Republic of Ireland as they beat Azerbaijan in a World Cup qualifier.
Robinson then netted a hat-trick in friendly win over Qatar.
And Ismael has now challenged the forward to replicate his form for his country for his club.
“The Irish legend is back,” the boss said with a smile.
“We were happy for him. It’s a great feeling for him to get the confidence for his country and for us, but now we need him to carry on.
“We’ve got some important games and Robbo is one of our best scorers, it’s important he continues in that way for himself and the team.”