49ers' Trey Lance All Smiles After Season-Ending Surgery, 'I Will Be Back'

Despite a broken ankle and season-ending surgery ... Trey Lance is in good spirits, sharing a photo from his hospital bed on Monday with a big smile on his face.

The 22-year-old 49ers star quarterback suffered the gruesome injury during the win over the Seahawks on Sunday -- breaking his right ankle in the first quarter.

SF head coach Kyle Shanahan announced after the game that Lance would need season-ending surgery ... and, on Monday, Lance said it all went well.

"Truly appreciate all of the messages and prayers," Lance wrote on his Twitter page. "Surgery was a success and I am ready to attack this rehab process."

"We will never understand why, but I trust that it’s all a part of His plan," the QB added. "I will be back better than ever. This chapter is going to make the story even greater!"

Jimmy Garoppolo took over for Lance and ended up with 154 passing yards, one passing touchdown, and the win. He said after the game he felt badly for his teammate.