McKinnie, who has had difficulties getting himself in condition for NFL play the last two seasons (first with the Minnesota Vikings and now with Baltimore), has not yet joined the Ravens at training camp.
"He contacted us through a representative. He is dealing with an issue right now," coach John Harbaugh told reporters Thursday. "I don't really want to speak for him on that. Just let him speak for himself on that when the time comes."
Could this keep the Ravens' starting left tackle from 2011 out long term?
"In all honesty, I really don't know," Harbaugh told reporters. "We should know more here soon."
Harbaugh did say that McKinnie will play left tackle should he rejoin the team.
The 32-year-old, 10-year veteran wasn't the only significant player missing Thursday.
All-Pro defensive tackle Haloti Ngata was reportedly placed on the physically unable to perform list. Harbaugh told reporters Ngata tweaked his hamstring during his conditioning test.
"We're going to take it slow and make sure he is OK," Harbaugh told reporters.