Champions in 1930 and 1950, Uruguay go into Friday's Group H decider with a point from two matches and not a single goal scored, their cast of big-name strikers stuttering and lacking support from midfield.
"It's up to all of us to feel that confidence we have played with in the past when we had to play knockout matches. Even friendlies, we play with joy, we are a joyful, dynamic team and we have to recover that," Alonso said.
"We need to let ourselves go and feel we are enjoying this party, this celebration of football and give it our all and feel confident."
"I believe in my players. We have to reiterate this and fill our players with confidence so they can play freely as we have on so many occasions."
Uruguay's brand of football has earned the country a place at 14 World Cups but they are on the brink of exiting at the group stage for the first time in 20 years.
Their biggest names, including Real Madrid's Federico Valverde (24), Tottenham Hotspur's Rodrigo Bentancur (25), Liverpool's Darwin Nunez (23) and veterans Edinson Cavani (35) and Luis Suarez (35) have had little impact in Qatar, despite the team being widely tipped for another deep World Cup run.
Alonso said they felt dismayed at being in the position they are in, needing a win to advance against a strong Ghanaian team.
"We understand how important this match is and what is at stake and what's on the cards," Alonso said.
"We're still alive with a chance to go through if we believe in ourselves and it's a great opportunity that we want to seize."
Striker Suarez playing in his fourth World Cup, said he was calm about the match because adversity was nothing new for Uruguay.
"We're here at the World Cup, this is the reality, we would love to be in a different situation," he said.
"We are Uruguay, we are used to be in this kind of struggle. It upsets me ... we have good enough players to be in a different situation but we usually rise to the challenge."
Follow all the action from Uruguay versus Ghana on Flashscore.
