The 15-time Copa champions were in fine form in Belo Horizonte on Sunday, sweeping 10-man Ecuador aside with minimal fuss to move top of Group C.
Nicolas Lodeiro gave them an early lead before Jose Quinteros was sent off, and Edinson Cavani and Luis Suarez scored before the break to capitalise on the numerical advantage. Arturo Mina's second-half own goal wrapped things up.
Uruguay's victory was as emphatic as their preparations were worrying, with key players suffering injuries in the first half of 2019.
Barcelona striker Suarez underwent knee surgery in May, while Cavani missed the business end of Paris Saint Germain's season with a hip issue.
Tabarez subsequently paid tribute to the team's professionalism for coming through such issues and securing a strong start to the Copa.
"I always expect the best from these players here in the national team, because they have a huge commitment to the team," he said.
"But there were some cases like Suarez, this is the first game he plays after his injury, he played just some training matches we did.
"Cavani, he also had an important injury and just played the last games in his league. [Cristhian] Stuani, Jonathan Rodriguez [also had problems] – there was a lot of uncertainty.
"We can almost be completely happy about this win, but [Matias] Vecino has muscular pain and we will look at the nature of it [on Monday] in Porto Alegre.
"Football always carries its surprises, we must be ready for everything. Maybe we should have rested those players I said, but just when I was going to change Suarez, we got this [injury] with Vecino.
"However, we are glad about this [win] because we assumed this game was going to be hard, as every game is in South American competitions, and this win is something important for us, it is what we wanted."
Uruguay will face Japan in Porto Alegre in their next match on Friday, before facing off against defending champions Chile four days later.