Keselowski accused Ragan on Twitter of getting an unfair advantage by switching to an outside lane before the green-white-checkered restart in Sunday's race. He tweeted it was "blatantly wrong" and that he was "mad as hell about the finish."
As Keselowski later discovered, Ragan was told by NASCAR to switch lanes prior to the restart after the governing body realized there was a mistake in the order. NASCAR also radioed the switch to Keselowski and his spotter, but neither heard it and both were unaware the change was being made until about a half-lap before the restart.
After the race, Keselowski responded with a series of tweets that included: "I'm happy as hell a small team won. Doesn't change the fact that the restart was blatantly wrong. mad as hell about that finish. We were suppose to line up 10th when the 34 switched lanes entering 3 before green. That lane won. BS."
But Keselowski changed his tone Tuesday in a written apology posted on his website.
"I finally had a chance to digest what happened at the end of the Cup race at Talladega on Sunday," Keselowski said in the apology. "I owe David Ragan and his fans an apology. I placed blame on David Ragan for the restart lineup confusion when it wasn't his fault.
"I was very passionate about the finish because I thought we had a chance to win the race if I restarted the race in the 10th position instead of ninth. Passion is a very important characteristic to a champion driver. That passion is not something I will apologize for. The outside line -- the 10th spot, in particular -- was a huge advantage over the 9th position. David executed that positioning perfectly for the win."
Keselowski emphasized that he did not mean to "detract" from Ragan's victory and attempted to explain his confusion regarding the restart.
"Basically what happened is that, when the yellow came out at lap 184, the lineup was supposed to be Scott Speed, myself and David," Keselowski said. "We were actually lined up David, Scott and me because we were unsure what the lineup was. NASCAR did not change this before opening pit road, so by procedure we were lined up in the proper positions. NASCAR made a last-minute lineup change that we missed as we were getting ready to go back to green. David attempted to make it right by letting me go at the start/finish line with one to go. I thought he was attempting to change the pylon because the order is supposed to be set before pit road opens.
"With the multicar wreck, the rain and the impending darkness, it is easy to see how NASCAR could have made that mistake. It was a confusing time for all of us. I want to send a sincere congratulation out to David Ragan and everyone at Front Row Motorsports. It was a very cool win for our sport."