OAKLAND -- Ten days after John Jaso landed on the seven-day disabled list with a concussion, Oakland's left-handed-hitting catcher is still experiencing the effects of being hit in the mask by foul tips three times in four games.
Jaso said he wakes up to ringing in his ears every morning "like I was at a rock concert the night before," and he won't fly with his teammates to Cincinnati, though joining the A's in Toronto is still a possibility.
A's manager Bob Melvin said Jaso will go through some "extensive testing" Saturday, and he can begin baseball activity in the next couple days if all goes well.
Jaso added that the A's have been in contact with a "concussion expert in Pittsburgh," which likely means Dr. Michael Collins, a University of Pittsburgh doctor who consulted with Brandon McCarthy after his head injury last year.
Jaso was required to spend at least seven days on the DL with his concussion, and he'll be transferred to the 15-day DL if he is not reinstated after 14 days, which may happen, considering he's yet to participate in any physical activity since the incident.
"I haven't started any activity to get my heart rate up," Jaso said. "I'm itching for that."
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. Jeff Kirshman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.