Via NFL.com's Gregg Rosenthal:
"I've definitely noticed it," Harbaugh said in comments distributed by the team. "You don't know what it is. Even when people say what it is, you don't know that that's what it is. For this, throw it out, or it's that. But that's usually the agents of the players themselves saying it's, for example, Adderall.
"But the NFL doesn't release what it actually is. So, you have no idea. You're taking somebody at their word that I don't know that you can take them at their word, understanding the circumstances."
"Play by the rules," Harbaugh said he told his players. "And you always want to be above reproach. Especially when you're good, because you don't want people to come back and say they're winning because they're cheating."
The most recent Seahawk hit with a suspension was Bruce Irvin, but according to Lindsay H. Jones at USA Today Sports, Brandon Browner, Winston Guy, Allen Barbre and John Moffitt have all been punished since 2010.
What do you think of Harbaugh commenting on Seattle?
Cornerback Richard Sherman was also subject to a suspension, but he successfully appealed it in December of last year. Still, the Seahawks lead the league in PED-related suspensions over that span.
As such, head coach Pete Carroll is focusing extra attention on prevention, per Jones.
If nothing else, Harbaugh discussing the Seahawks' most notable major issue in a very public manner adds some serious fuel to a rivalry that has been quickly gaining momentum in the past few years.
The history between Harbaugh and Carroll started when they were at Stanford and USC, respectively, and had an infamous postgame handshake:
Last year, the 49ers and Seahawks both played at an extremely high level (and split the season series), thus taking the rivalry to an entirely new level.
Yahoo! Sports' Doug Farrar discussed the two head coaches' seemingly disgust for each other:
I've seen coaching rivalries, and I've seen thinly veiled contempt. Carroll/Harbaugh seems to rest somewhere in the middle.— SC_DougFarrar (@SC_DougFarrar) June 11, 2013
This is quickly becoming one of the NFL's most heated rivalries, and although we're only in June, we are already seeing subtle shots being taken.
Imagine what these two teams have in store for each other come September.