The Baggies signed the Nigeria forward from Ukrainian side Dynamo Kiev for a club-record transfer fee on a three-year deal earlier this month.
The fee was believed to be in the region of £10m.
"I don't know much about Brown Ideye," admitted Irvine when asked about his team's big summer signing in quotes picked up by Sky Sports.
"I've not seen him live, but people we trust have done.
"It's not necessarily something that is detrimental to me not to have seen him live, though ideally I would like to because that's how I like to do my work.
"But we've done our research on him and what we have done is found decent players in the past in this way."
The 25-year-old forward arrives at The Hawthorns with an impressive record having scored 74 goals in 182 career league appearances.
Brown has scored five goals in 24 appearances for Nigeria and was called up to their 2010 World Cup squad in South Africa.
When the signing was announced Irvine said that Brown was "a quality striker and I'm looking forward to working with him.
"He's a strong, quick, powerful player who likes to get in behind defences and has plenty of Champions League and international experience," said the Scot in the official release announcing the signing.
- Sports & Recreation
- Brown Ideye
- Dynamo Kiev