Bayern Munich say there is still no timeframe for Franck Ribery's return to action and blamed his continued fitness troubles on a failure to allow the Frenchman adequate healing time.

Ribery, 32, has not featured for Bayern since limping out of the 7-0 Champions League victory over Shakhtar Donetsk with an ankle injury on March 11.

The medical team, then headed up by Dr. Hans-Wilhelm Muller-Wohlfahrt, had been confident he would make a swift recovery and he returned to team training prior to the home defeat against Borussia Monchengladbach on March 22.

However, his recovery suffered a setback and coach Pep Guardiola told reporters earlier this month: "I don't know when he'll return. Ask the doctors."

Muller-Wohlfahrt and his medical team have since resigned, claiming they were blamed for the absence of several players during the recent 3-1 defeat to Porto, and Bayern sporting executive Matthias Sammer has acknowledged that mistakes were made with the winger.

"We made the steps [towards his comeback] too fast," Sammer told kicker. "We now need to make sure that we slowly sort him out. Nobody can predict the time he needs."

Franck Ribery, Medhi Benatia and David Alaba were among the Bayern stars injured for this week's 6-1 victory over Porto. Dennis Grombkowski/Bongarts/Getty Images

Kicker reports that Ribery is currently limited to cycling to maintain his fitness, and that he has no prospect of facing Borussia Dortmund in the DFB-Pokal semifinal on Tuesday. He is also said to be a major doubt for the first leg of their Champions League semifinal, which will be played on May 4 or 5.

"It's really frustrating him," Sammer added. "It's a damn stupid situation for him."

However, Bayern's injury issues are starting to ease, with Javi Martinez and Arjen Robben both nearing a return to fitness.

Martinez, who has just returned to team training eight months after suffering an anterior cruciate ligament tear, told the club's official website: "It's just fantastic! I'm overjoyed. I know I have a lot of work ahead of me yet. I hope I can pick up a few minutes' playing time very soon."

An 'overjoyed' @Javi8martinez returned to team training today. Good to have you back, Javi! http://t.co/ihZ3vu1cJz pic.twitter.com/CwZvhosuiT - FC Bayern English (@FCBayernEN) April 23, 2015

Bild reports that Robben, who has been sidelined since the 2-0 defeat to Gladbach last month, will be available for the Champions League semifinals at the latest, while Sport1 believes he could be used as an impact substitute against Dortmund.

Meanwhile, Bayern CEO Karl-Heinz Rummenigge has told Bild that his relationship with Muller-Wohlfahrt remains "intact."

Rummenigge was reported to have clashed with Muller-Wohlfahrt but he said the doctor could take a new role as an advisor in the future, explaining: "He's a man with a lot of experience."

Muller-Wohlfahrt, who remains the German national team's doctor, will also continue working with several of the club's players, with Robben having told ZDF this week he would continue receiving treatment from the 72-year-old.

"The players who are currently injured will continue to be treated by Dr. Muller-Wohlfahrt," he said. "If Arjen Robben, or someone else, trusts our [sic] doctor, we will not only accept it, but moreover respect it."