The 30-year-old Galatasaray striker, who limped off the training pitch on Tuesday with doctors fearing a thigh abductor rupture, managed a full training session on Thursday evening without any problems.
"He did not complain and he's got the green light. The treatment will continue, but it looks very well. It's up to the coach now," the Czech team's chief doctor Petr Krejci told the CTK news agency.
Baros, who has scored 41 goals in 89 games for the national team, was top scorer at Euro 2004 when the Czechs reached the semi-finals.
He won the UEFA Champions League with Liverpool in 2005, but his form has slumped since then, with the player featuring as often on the gossip pages as the sports pages.
Still, he is the first-choice striker for Czech coach Michal Bilek at the tournament co-hosted by Poland and Ukraine.
Runners-up in 1996, the Czechs will play all three Group A games in the southern Polish city of Wroclaw near the Czech border.
After Russia, the Czechs will face Greece - who beat them in the Euro 2004 semi-finals before going on to lift the trophy - on 12 June and co-hosts Poland on 16 June.