The two sides will be hoping to make a fast start with co-host nation Romania and Spain also present in Group B.
Match preview
Having not qualified for this tournament since 2011, Ukraine will be aware that they are one of the outsiders to make an impression on this occasion.
However, the presence of Chelsea winger Mykhaylo Mudryk has provided the nation with a significant boost, even if he is unlikely to be considered for the opening game due to representing the senior team on Monday.
The squad required some star quality to make their opponents stand up and take note with 17 of their 23-player squad playing in their homeland, but they can be relatively content with their form heading into this competition.
Three wins and three draws have been recorded in seven matches, their only defeat coming at the hands of Italy by a 3-1 scoreline in March.
After only finishing three points behind France in their qualifying group, Ukraine came from behind in their playoff tie with Slovakia to prevail 5-3 on aggregate.
Croatia had to work even hard to progress through to the finals, finishing 3-3 on aggregate with Denmark before overcoming their opponents 5-4 in a penalty shootout.
Dragan Skocic's side had previously finished two points adrift of group winners Norway, but they head into this competition on a seven-game undefeated streak.
That includes a shock 2-1 victory over England on away territory, yet this is a squad that features just one player that has scored more than twice in Under-21 internationals.
Nineteen-year-old forward Gabriel Vidovic may be one to watch, the Bayern Munich youngster having been allowed to spend the most recent campaign on loan in the Netherlands with Vitesse.
Ukraine Under-21s form (in all competitions):
Croatia Under-21s form (in all competitions):
Team News
Barring any injury issues, it is plausible that Ukraine will line up as they did for the 2-2 draw with Republic of Ireland on June 16.
Goalkeeper Anatoliy Trubin and Mudryk are unlikely to be considered due to their involvement in Ukraine's fixture with Malta in Euro 2024 qualifying on Monday.
Croatia are missing two players from the triumph over England, both of those alterations needing to be made to their backline.
Mauro Perkovic looks the most likely option to be drafted into the centre, while Niko Sigur could make his debut at right-back with David Colina moving to the left.
Ukraine Under-21s possible starting lineup:
Nescheret; Sych, Taloverov, Batagov, Vivcharenko; Bondarenko, Brazhko, Kryskiv; Kashchuk, Sikan, Viunnyk
Croatia Under-21s possible starting lineup:
Kotarski; Sigur, Soldo, Perkovic, Colina; Baturina, Prsir, Kacavenda; Frigan, Beljo, Vidovic
We say: Ukraine Under-21s 1-1 Croatia Under-21s
With both teams having been required to come through the playoffs, this should make for a hotly-contested match. With that in mind, we can only back a draw, a result which each side would take ahead of their upcoming fixtures.