The Hammers landed Coufal from Czech Republic giants Slavia Prague for a fee said to be in the region of £5m on a three-year deal last week.
Coufal is in familiar company at the London Stadium with countryman and former Slavia Prague team-mate Soucek sharing the Irons dressing room with him.
Moyes revealed that Soucek’s glowing reference on Coufal’s quality ultimately convinced the club that the 28-year-old was the right signing.
The Hammers boss added that the Coufal’s experience playing in the Champions League, coupled with his minutes on the international stage, made a strong case for why the right-back deserved to be at the London Stadium for the next few seasons.
“The biggest thing about him is his experience, his knowledge”, Moyes told West Ham TV.
“That was the reason we thought he would be helpful for us at this time.
“We saw someone who had played in a lot of big games – Champions League games – and who plays for his country.
“He also came really highly recommended from Tomas, so that helped us make our minds up.
“I don’t think he disappointed anybody on his debut, that was for sure.”
Coufal made his debut for the Hammers against Leicester City on Sunday in the Premier League and marked his league bow with a clean sheet in his team’s 3-0 win.
