Oleksandr Usyk is unbeaten in 20 pro fights as a cruiserweight and heavyweightVenue: Tarczynski Arena, Poland Date: Saturday, 26 AugustCoverage: Follow live text coverage and reaction on BBC Sport website & app from 21:00 BSTUnified heavyweight champion Oleksandr Usyk paid tribute to Ukraine as he came face-to-face with Daniel Dubois before their fight in Poland on Saturday.There was little fighting talk at Thursday’s news conference, which coincided with Ukraine’s Independence day.Usyk, 36, received a gift from the Ukrainian army – an icon painted on a wooden board used by soldiers.Thousands of Ukrainian refugees are expected to attend the fight.The media-only event took place exactly 18 months after Russia’s invasion began and 32 years since Ukraine declared independence from the Soviet Union. Mostly Ukrainian broadcasters and reporters filled out the press room of the Tarczynski Arena, an open-air stadium home to football club Slask Wroclaw which will host Saturday’s bout. WBO, WBA (Super) and IBF champion Usyk, dressed in a striking, embroidered green shirt, entered the room to a polite round of applause from a strong Ukrainian press turnout. An understated Dubois followed, wearing a grey matching tracksuit. Former world champion Prince Naseem Hamed joined the fighters and promoters at the top table.”Yes D, how you doing baby?”, he asked a smirking Dubois. The British superstar’s son, Aadam Hamed, makes his professional debut on the undercard.Usyk’s promoter Alexander Krassyuk set the tone immediately at the start of the event with a rallying cry about Ukrainian war efforts.”It is a special day for many of us. Our soldiers are struggling on the front line defending our country,” he said. “Ukraine is fighting for our independence. God bless Ukraine and God bless the people of Ukraine.”Former undisputed cruiserweight champion Usyk won his first world title in Poland as an away fighter against Krzysztof Glowacki in 2016. This time he will fight in the nation under very different circumstances. Around 40,000 fan are expected to attend on Saturday, made up largely of Ukrainians residing in Poland. Approximately 1.5m Ukrainians have fled to Poland since the invasion began. Usyk was mobbed by fans at Wednesday’s public workout, and later entertained those waiting in the sweltering heat by juggling, dancing and rapping. The champion kept his speech short but direct, making a point to thank his family and the soldiers in Ukraine.”My preparation is all good,” he said. “We did a lot of work. We played football, we danced.”Dubois answered only one question, saying he was “ready” and “confident” to upset the odds. The Englishman is a huge underdog fighting in his first world championship bout against the unbeaten Usyk.Speaking to BBC Sport earlier, the WBA’s mandatory challenger said: “Everything is about timing. “It’s about this time, for me right now to go out there and prove to the world that I am the best, and take the belts home.” “This is the time of the young dog,” he added. “The young blood to come in here and steal the show.”Analysis – A serious champion faces a big underdogUsyk signed autographs and danced at the open workout on WednesdayAn undefeated record, three heavyweight world titles and the hopes of a nation are on the line for Usyk this weekend. If he is feeling the pressure, he is very good at hiding it. Usyk. as he always does before a big fight, showed no signs of nerves. He lives for these occasions. Usyk is so often an extravagant figure at media events, cracking jokes and playing the showman. But here he was far more serious and direct in his message of support to Ukraine, choosing to speak English as he did so.A shy and reserved Dubois has never been the greatest talker. He has come out of his shell a little over the years, but has not become a wordsmith overnight, and his speaking time here was short but sweet.For the first time in his professional career, Dubois is an underdog. Sparring partners and coaches all talk about the 25-year-old’s frightening power, but after defeat to Joyce and being dropped three times in his last outing against Kevin Lerana, there are question marks on his ability to shine when it really matters – under the bright lights and in front of raucous crowd.