"Who knows what will happen?" the source says. "They do love each other. They are very good friends and will continue to be as strong and as good friends as they can be."
The "Blurred Lines" singer seemed to made it clear on Thursday that he hasn't completely given up on his eight-year marriage.
Arriving in Washington D.C. for a concert, the 36-year-old was smiling as he walked through the airport and when quizzed by a TMZ videographer about the state of his relationship, he said, "I'm just trying to get her back."
The couple – who have a son, Julian, 3 – announced their split on Monday, saying in a statement, "We will always love each other."
"I can truly see them being the best of friends no matter what happens," the source says of the pair who met when they were teenagers. "They still admire each other. She'll always be his biggest fan and he'll always write songs about her and put her on a pedestal."
Reporting by MARY MARGARET