Originally published on ProWrestlingSheet.

"The Architect" Seth Rollins smiled from ear to ear before getting knee surgery that could keep him out of action for months -- but you won't be doing the same once you see his gross operation video.

Rollins happily posed with his doctor before going under the knife this week in Birmingham, Alabama ... in a surgery the former champ described as a basic reconstruction of his knee.

As we previously reported, Seth Rollins suffered tears in his right ACL, MCL and medial meniscus which will keep him on the shelf for quite some time.

In a WWE.com interview over the weekend ... Rollins said he was overwhelmed by the amount of love he received from wrestling fans following his injury -- and thanked them all for the support.

Warning, the operation video below is graphic. You've been warned.