England manager Roy Hodgson has not ruled out changing formation after Saturday's 1-1 draw against Russia.
Eric Dier's clinical 73rd-minute free kick looked to have given England their first-ever win in the opening match of a European Championship, only for Vasili Berezutsky to head home an injury-time equaliser.
Victory would have vindicated the manager's decision to revert to 4-3-3, recalling Adam Lallana and Raheem Sterling and deploying Wayne Rooney in midfield for the first time in his long international career.
Hodgson saw plenty of positives at the Stade Velodrome but stressed the system and personnel were under constant review ahead of Thursday's key game against Wales.
Leicester's Premier League title-winning striker Jamie Vardy was an unused substitute in the game, and could be in line for a recall against Wales.
"We think about it all the time," he said. "The team depends upon how you see individuals you are working with, and how you build a team to make best use of their qualities.
"We thought, going into this game, we'd been pleased with Raheem and Adam, and with Harry Kane, so we thought that would be our best attacking option.
"We could change it for the next games. When we analyse the game, and start preparing for the next game, there'll be a lot of things that we'll want to take forward and hopefully we'll be able to put the memory of that last-minute goal behind us. It won't take us long to get over it."
Hodgson admitted trying to replicate a previous iteration of the formation, used during the team's 100 percent winning run in qualification, during the draw against Russia.
"Lallana and Sterling and Kane...that's a direct replica of Sterling, [Danny] Welbeck and Rooney which we were using for long periods ahead of these finals," he said.
"We've been playing this system [and] if you take the successful period, we've had with two defeats in over 20 games."