Bilic's name already crops up when a Premier League job becomes available, while Modric has earned a £16.5million move to White Hart Lane from Dinamo Zagreb.
Spurs fans will get a glimpse of Modric on Sunday when they face joint hosts Austria in Vienna's Ernst Happel Stadium.
"I'm confident I'll live up to their expectations," said Modric. "I think I'll do well, but the most important thing is the team."
Modric explained the importance of Bilic to his development.
"We've been working together for three-and-a-half years and Mr Bilic trusted me from the start," he added.
"He trusted me to show what I can do on the pitch. It's a pleasure to be able to work with someone like him."
But Bilic admits losing Eduardo, their top scorer in qualifying, will be a factor after the Arsenal forward's sickening ankle injury in February.
"Losing Eduardo was a big blow for us," said Bilic.
"We're simply less good without him. I have other excellent strikers, but without Eduardo we're not the same team."