Koumas was set for a move to Cardiff City in the summer but it all went pear shaped. He was not training with WBA while the matter was up in the air and as a result he missed the Welsh games against Bulgaria, Czech Republic and Brazil.
Now his club future is sorted and he is playing again.
I spoke with Tosh all summer, he gave great advice and I thank him for that - now I aim to repay him," said Koumas.
"I have played in the last three games for Albion and I feel fine," said the highly talented playmaker.
"I am getting stronger with each game and I enjoyed the match on Saturday against Leeds, I feel I am just coming into form now.
"Now I hope to get the chance to show people what I can do. Things dragged on in the summer, and that shouldn't have happened.
"That was my own fault, I should have gone back to training earlier and I accept that was a mistake I made. Now I am just glad to be back and feeling good.
"I knew exactly where I was with John [Toshack]. I am here now with the squad aiming to do well for him.
"People do think I am a difficult player to handle, and that is unfair, but what can I do?
"If you look in from the outside people are always going to say that considering what has happened.
"But for Wales I have enjoyed my time in every squad I have played in, I do not want to be missing any more internationals. There are big games coming up I want to play in.
"I did not feel John gave me any ultimatums. The reason I wasn't with the squad last month was because I had not really had any pre-season training apart from what I did on my own.
"Any player would have said the same. But I am here now and I aim to do myself justice."