England cricket captain Andrew Strauss said Kevin Pietersen's actions were an issue of "trust and mutual respect".
Speaking at a news conference ahead of England's third Test against South Africa, Strauss referred to Pietersen's apology as "a first step definitely".
"It's going to be a long process. Unfortunately we have to address this issue, it's not one we can sweep under the carpet," the captain said.
When asked whether he could see Pietersen returning to the team, Strauss added, "Perhaps it's possible, perhaps impossible for there to be a way forward".