Seville and St Petersburg are replacing Dublin and Bilbao as Euro 2020 venues.
UEFA's executive committee was meeting on Friday to finalise plans after Bilbao and Dublin could not guarantee fan presence at matches.
"Seville and San Petersburg - officially" tweeted Boniek, "There is a bit of work ahead of us, we start over, camp, journeys, all logistics".
Guardiola admits to not having digital distractions: 'I don't have social media'
- The Super League is dead, but the revolution must continue - The Warm-Up
- Southgate a target for Spurs, United waiting on Sancho - Transfer Notebook
- Parker's Picks: Everton to shame Arsenal, Chelsea to be held by West Ham
Boniek is an official of the Polish FA and Poland were due to play games in Dublin and Bilbao.
'We were not involved' - Furious Klopp reacts to Super League furore
Arteta praises reaction of young Arsenal players after win against Villa
Three-time World Cup winner Pele turns 81