Former 49ers coach Jim Harbaugh had his fair share of battles with the Seahawks - and Pete Carroll - during his tenure in San Francisco.
Now the head coach of the Michigan Wolverines, it looks like there is no lost love between Harbaugh and the Seahawks.
The former wanted to dedicate one of his play calls to his rivals from the Pacific Northwest, using a playcard plastered with a Seahawks helmet.
The Seahawks Twitter account even had some good fun in responding.
The Wolverines dropped their season opener to Utah 24-17.
(h/t CBS Sports)