Pocognoli arrived at The Hawthorns on a three-year deal from Bundesliga outfit Hannover, where he spent just over a year having moved to Germany in January 2013.
The 26-year-old - capped 12 times by the national team - is the first Belgian to play for West Brom since Lukaku, who scored 17 goals during an impressive season-long loan from Chelsea in 2012-13.
"I follow the Premier League so I know West Brom is a good club," said Pocognoli, who missed out on selection for the FIFA World Cup after an injury-interrupted season.
"My mate Romelu Lukaku played here before so I know a little bit about the club, the history. It's a good club, with a good image and for me it's exciting.
"I spoke to Romelu. He gave me the best opinion on the club. He was very positive and said to me that if I have the opportunity to go there then I should take it.
"His experience here was great. He scored a lot of goals, his relationship with the supporters was very good too.
"I received a great welcome from the group, the trainer and the staff."
