All eyes will be on five-time Ballon d'Or winner Ronaldo at Fisht Stadium in Sochi on Saturday and Tabarez understands the task facing Uruguay – who qualified as Group A winners – in their pursuit of the quarter-finals.
"I believe that Ronaldo is one of the best strikers in the world," Tabarez said. "What Ronaldo has on top of these qualities is that he is the leader of that team. There is not a single player that contain him. We will have to work collectively to try to contain him, in order to try to limit the effect he can have."
Tabarez added: "It will be a great match. We will just see how things pan out. We have already demonstrated this. We don't lose any sleep over this. We won't give it more importance than that. We won't be obsessed. It's difficult to win, especially if you're not focused.
"Nine of the [Portugal] players on the pitch [in their last game] are European champions. That speaks of their quality. We've been preparing for a while - 12 years we've been working together. We've been obtaining goals and objectives, step by step. Given the limits we have as a footballing country, we've made it to the World Cup. We've started showing what we're trying to achieve. We're closer than ever to achieving our real objectives and we want to do this at the World Cup. I think we have a certain calmness in facing it."
Asked about Uruguay's preparations, Tabarez – whose side needed a dramatic late winner in their opener against Egypt, told reporters: "You're never fully, fully okay. I remember a time when I started out as a coach and someone told me teams are like glasses, if you think everything is going right, suddenly someone stumbles down the stairs and suddenly the glass breaks.
"We have 23 players and only fielded 17 so far. We've seen improvement since the first match. It's true there were better days. That doesn't mean we have more arrows in our arsenal. We always study our aspects and qualities of our opponents. We do try to adapt to that. That's important elements for us. We have great motivation. It would be wonderful to beat Portugal. We see it is a possibility. We will do everything to achieve victory."
Star forward Luis Suarez has led the way for Uruguay with two goals in three games at the World Cup.
After a frustrating opening match against Egypt, Suarez scored the winner against Saudi Arabia before getting on the scoresheet as Uruguay eased past Russia.
"Of course [we're] much better than the first match," Suarez said. "You're trying to achieve the best and be critical in your self-appraisal and that was the case in the first match. After the match, you start thinking and you speak with the other players and you speak to the coach. Then you don't need additional motivation.
"Tomorrow is highly motivating. They're reigning European champions. I feel that motivation. I'll prepare accordingly. I can tell you that no one is holding back in anyway and you will see that when the match starts."