"Of course it's going to be nice to be able to play against Ronaldo. We want to measure ourselves up against the best," said Ten Hag at the pre-match media conference on Tuesday.
Ronaldo is a doubt for the game because of a thigh injury sustained a fortnight ago while playing for Portugal in the Euro 2020 qualifiers.
He last played for the Italian champions in the previous round against Atletico Madrid, scoring a hat trick to lead Juventus to a thrilling comeback victory.
Juventus coach Massimiliano Allegri at the weekend said he was confident the 34-year-old would be ready for Wednesday's game in Amsterdam, although he would still need to pass a late fitness test.
The Italians are already without midfielder Emre Can and central defender Giorgio Chiellini, neither of whom travelled for the quarter-final first leg tie at the Amsterdam Arena.
"Juventus will miss his experience. But just like all the other top teams in Europe, they have enough good players to replace him," said Ten Hag.
De Jong, who is moving to Barcelona at the end of the season, suffered an ankle injury in last Saturday's 4-1 league win over Willem II Tilburg but his availability is a boost for Ajax, who knocked out holders Real Madrid in the last 16.
"The bar is now raised again, but it is challenge we are looking forward to.
"The challenges are getting more difficult. We've already on a few occasions this season surpassed expectation, and we want to do that again tomorrow night," the Ajax coach added.
(Reporting by Mark Gleeson; Editing by Hugh Lawson)
