United States international Christian Pulisic is set to testify as a witness in the trial against the man who admitted setting off three explosive devices as Borussia Dortmund's team bus headed to a Champions League match in April 2017.

Pulisic, 19, has been summoned to Dortmund's district court as a witness and is scheduled to testify on May 14 alongside teammates Nuri Sahin, Sokratis Papastathopoulos, Raphael Guerreiro, Shinji Kagawa, Lukasz Piszczek and Julian Weigl.

Earlier this week, two former players, Sven Bender and Felix Passlack, as well as current players Marcel Schmelzer and Roman Weidenfeller testified in the trial against the 28-year-old, who has been identified only as Sergej W. in keeping with German privacy law.

Borussia Dortmund's Christian Pulisic will testify at the bus attack trial on May 14. Peter Lous/Soccrates/Getty Images

The players testified that they, at least in parts, have not got over the attack on the bus, which left defender Marc Bartra with a severe arm injury that required surgery.

Dortmund staff member Fritz Lunschermann, meanwhile, told the court that players such as Sahin, Sokratis, Gonzalo Castro and "Marc Bartra, of course" were still affected by the aftermath of the attack.

Bartra joined Real Betis from Dortmund in January, one day after appearing as a witness in the trial.

Former head coach Thomas Tuchel, who testified on Monday, said that the attack had no lasting effect on him, but claimed that he believed he would still be Dortmund's coach if it had not been for the attack.