Forsythe, who battled plantar fasciitis in his right foot for most of March, felt a "pop" in the foot in his last Spring Training game on March 26. He then returned to San Diego the following day where it was determined that he had partial tear.
In Forsythe's case, the connective tissue that supports the arch on the bottom of his foot essentially pulled away from or became detached from the heel bone.
Forsythe had his foot placed in the boot on March 27 and has been wearing it ever since. He has been told he needs to wear it one more week. The boot immobilizes the foot and promotes healing.
"We were going to try and manage the pain, but once it popped, I couldn't stand it," said Forsythe.
Forsythe would have likely filled in for Chase Headley at third base had he been healthy. Now, Forsythe is trying to get healthy himself, though there's no real timeline as to when he might return.
"We have to exhibit a lot of patience with this one," cautioned Padres manager Bud Black.
There was some good news to come from all this, Forsythe said.
"They think that after this it will be fine," Forsythe said.
Like Headley, who fractured the tip of his left thumb on March 17, Forsythe will need a stint in the Minor Leagues before he's able to return to the big leagues.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.