West Brom keeper Foster hails "livewire" Yacob
Foster praised him for the quiet, efficient and no-nonsense approach he has shown in making a quick transition to English football.
"He's amazing," said Foster to the Albion website. "I'd never heard of the bloke. I'm not disrespecting him but I didn't know anything about him.
"I'm not the biggest football fan in the world anyway - but he's not someone I'd come across. He came into training on the first day and he's exactly like he is now.
"He doesn't say a word, he comes in and just opens up and smashes everyone in training.
"He's a little live wire."