Christensen fractured his collarbone during pre-season and made his return via the NEAFL over the weekend.
He collected 24 disposals, laid a game high 10 tackles and kicked a goal.
However, he pulled up sore from the win, with scans revealing a crack had developed in the surgical steel plate that was inserted to strengthen the collarbone.
Christensen first broke his collarbone in round 11 last season, before breaking it again during pre-season.
“Allen has worked really hard to get back into excellent shape not once, but twice, over the past 12 months, and we are all incredibly disappointed for him,” Brisbane Lions Football General Manager David Noble said.
“This is a very unusual problem, certainly one that we have never seen before, and we are frustrated that it’s happened, so we will seek some clarity around how it could occur.
“Our overriding concern is for Allen’s wellbeing, and we all agree it’s best to take a conservative approach to ensuring he gets back to full fitness.
“We are providing him all the support he needs and Allen has already spoken about channelling his efforts for the rest of the season into continuing to develop the fantastic leadership he has shown in past months.”