After upending Ravens tight end Maxx Williams, Alonso trotted toward the sideline before looking back onto the field. Alonso continued to retreat and ultimately found himself standing right next to Baltimore coach John Harbaugh.
"I kind of just went over there, and it was the wrong sideline," Alonso said of his gaffe. "It happens."
What also happened is the Dolphins were flagged for a delay of game penalty.
Alonso dismissed the notion that he sustained a concussion after his jarring hit on Williams.
"Not at all. If you can see the whole thing, I did a flip over the guy and I went over there with my head down," Alonso said. "I was totally fine. People obviously right off the bat were like, 'Oh my God, he's concussed.' I'm like, 'No.'"
Alonso admitted to being confused as to whether he could run back on the field since the Ravens were lined up to run a play.
The 28-year-old received plenty of ribbing once he returned to the Dolphins' sideline.
Kiko Alonso accidentally went to the wrong sideline 😂😂😂 pic.twitter.com/f3efJuChs6— The Checkdown (@thecheckdown) August 25, 2018
"They were all saying stuff," Alonso said of his teammates' reaction. "I'm definitely going to hear that for a while, and it's well-deserved."