The world players' union FIFPro said that Borussia Dortmund should not have played so soon after Tuesday's attack on their bus and wants clear guidelines on dealing with similar incidents should they happen in the future.

Dortmund's Champions League quarter-final first leg at home to AS Monaco was postponed by 24 hours after three explosions went off near the bus as it made its way to the stadium, injuring Spanish defender Marc Bartra.

The game was immediately rescheduled for Wednesday where Monaco ran out 3-2 winners.

FIFPro said that the game could have been delayed for longer, regardless of any knock-on effect to the fixture list.

"Players are people first and their emotional state must be taken into account. This comes before any other consideration," the Dutch-based union told Reuters.

"We believe the incident was serious enough to warrant a longer delay than 24 hours, irrespective of the challenges it would have posed for travelling fans and to adjust the match calendar."

European soccer body UEFA took the decision to reschedule the game on Tuesday night, saying it had consulted both clubs and police authorities.

"A revision of this incident needs to be carried out together with FIFPro and other key stakeholders to create clear guidelines on how to act in such extreme circumstances," FIFPro said.

Dortmund coach Thomas Tuchel said after the game on Wednesday that his team had not been ready to play and had found out about the rescheduling after receiving a text message from Switzerland, where UEFA is based.

Following Tuchel's comments, UEFA reaffirmed in a statement that the decision was made at the stadium on Tuesday night "in cooperation and complete agreement with clubs and authorities".

"UEFA was in touch with all parties on Wednesday and never received any information which suggested that any of the teams did not want to play," it said.

Dortmund chief executive Hans-Joachim Watzke said on Tuesday night that there was no alternative to playing on Wednesday.

"We have a very tight fixture list," he said on the club's website. "The second leg is next week. There is no possibility to wait for Thursday. The Monaco team cannot stay here. They also have a game at the weekend."

On Wednesday, he said he had "appealed to the team to show society that we do not bend before terror".