The Baggies are in advanced talks to re-sign the Turkish international who impressed at The Hawthorns while on loan from Celta Vigo in 2021.
Now a free agent after leaving the Spanish side, Yokuslu is expected to complete his return to the club in the coming days.
Asked how close Albion are to sealing a deal for the 28-year-old, Bruce said: "We are still trying our best.
"We are still hopeful otherwise I wouldn't have gone public with it.
"But where it sits, we'll just have to be patient for a little bit longer."
Asked if there are any other additions in the pipeline, the boss added: "My job is to never be finished and to keep knocking on the door to improve the quality.
"I believe the big ones, the real big clubs of our country are all on tour.
"They are all taking their young ones (who are likely to be available for loan) with them so I still think there is a bit of work to be done in those areas so we'll see."
Meanwhile, Bruce confirmed Grady Diangana will go for a scan this morning after twisting his ankle during Albion's 1-1 draw at Crewe on Saturday.
The winger has impressed in Albion's four pre-season outings so far.
Diangana was forced to come off at half-time during the friendly against Crewe on Saturday – although Bruce is confident the injury isn't too serious.
"He has twisted his ankle, unfortunately," the boss said.
"We don't think it's anything too severe. But we'll see.
"We'll have to wait until the scan on Monday morning."
Bruce also confirmed Callum Robinson missed the game at Crewe after picking up a dead leg in the game at Northampton last Wednesday.
The Republic of Ireland international has been linked with a move to Preston North End.
"Callum missed out altogether with the knock he picked up against Northampton," Bruce confirmed.