Sypniewski was carted off the practice field on April 18 when making contact with linebacker Antwan Barnes. The team remained cautiously optimistic, but following recent surgery the team determined that Sypniewski will not play again this year.
"It looks like now we're not going to have him back,'' Harbaugh said. "He had surgery. The ligament tore off the bone, and the piece of the bone that came off the ligament shattered, which made it a situation where it's going to be 6-9 months [to recover].''
Sypniewski became an important part of the Ravens offense last season when starter Todd Heap went down due to injury. Sypniewski had his best year in 2007, where he recorded 34 receptions for 246 yards and a touchdown.
James Walker covers the NFL for ESPN.com.