Maheta Molango will sign for Albion with a warning from manager Mark McGhee.
Molango, 22 on Saturday, has impressed with three goals in two games on trial for the Seagulls.
Albion had hoped to sign Molango today but McGhee said: "We were under pressure time-wise due to training, travelling to Weymouth for tonight's friendly and getting the contract drawn up.
"We are in the final stages of negotiations with Maheta's representatives and I expect him to sign tomorrow.
"We will wait until we've got him signed and sealed before we reveal details like the length of contract."
McGhee insisted his new striker will have to adapt to the physical nature of English football to succeed in the Coca-Cola Championship.
Molango, a former Atletico Madrid reserve, did not seem too pleased with the treatment he received during the 3-0 friendly victory over Crawley on Saturday when he scored twice.
McGhee said: "He was clattered from behind and, as much as referees will stamp on that, it still happens.
"Maheta has got to get used to that. He has to be prepared to get up and get on with it.
"We're not a team who are prepared to tolerate any kind of continental displays of feigning injury.
"We expect our players, unless they are injured, to get up and get on with it.
"I've told that to Maheta in no uncertain terms and I think he will adapt. We have seen in his two that he has good pace, the right build and ability and can finish, but he's got a lot to learn about playing in the English game in terms of the physical side.
"We feel he's got to develop the physical side so he can go on and show we've signed a young player with great potential."
McGhee sees a comparison to ace striker Leon Knight and remains in the hunt for another front-runner.
He said: "We've got all different types of strikers. Maheta will complement someone like Chris McPhee but I think he is similar in some ways to Leon or Jake Robinson.
"So we're still looking for someone to play with Leon or Maheta, especially with the injury to Chris.
"We've no more news but we're still trying to bring in other people."
Albion will face an Arsenal under-21 side behind closed doors at the Gunners' training ground on Friday following tonight's fourth pre-season friendly at Weymouth.
McGhee said: "We sorted out the Arsenal match with Liam Brady (the former albion manager now in charge of the champion's youth set-up) and they set out the ground rules which suit us.
"We're looking forward to the Weymouth and Arsenal games and giving everyone a chance to prove they should be in the starting line-up for Reading.
Promoted Albion kick off their Coca-Cola Championship campaign away to Steve Coppell's Royals on August 7.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article