You can now add Alexander Gustafsson's name to the UFC's ever-growing inactive list.

The promotion announced on Friday that an injury has forced Gustafsson to withdraw from his June 20 fight against Glover Teixeira in Berlin. As a result, newly-crowned 115-pound champion Joanna Jedrzejczyk will defend her title against Jessica Penne in the new main event. It is unclear at this time what's next for Teixeira.

According to Gustafsson's manager Manos Terzitane, "The Mauler" has been dealing with back issues as of late, as well as other small injuries. Terzitane said the hope is for Gustafsson to return to action "around September," but they don't want to rush things. Surgery is not required.

"With only six weeks left, we decided to pull him off the fight as he is not able to have a proper training camp," Terzitane wrote via text message. "Instead [we'll focus] on rehab and let him come back 100 percent.

"[We] don't want to rush it this time. We want the world see the best Alex and we know that perfection needs time."

The Polish-born Jedrzejczyk (9-0) won the strawweight title at UFC 185 in March when she defeated Carla Esparza via second-round TKO. Penne (12-2), the former Invicta FC 105-pound champion, defeated Randa Markos in her UFC debut on the TUF 20 Finale in December. She made it to the semi-finals of The Ultimate Fighter 20 tournament, losing to Esparza following wins over Aisling Daly and Lisa Ellis.

Penne was scheduled to fight Juliana Lima May 30 in Brazil next. No word on what's next for Lima now.

A bit of history will be made on June 20, as this fight will mark the first time a title is defended live on UFC Fight Pass. The event will take place at the O2 World in Berlin.

It has been a week to forget for the UFC, as the promotion first lost Jon Jones due to legal troubles, then Khabib Nurmagomedov due to injury and now Gustafsson.