Los Angeles: Actress Kaley Cuoco and tennis player Ryan Sweeting reportedly "seemed miserable" before their decision to part ways, even during romantic nights out.

Kaley Cuoco
Kaley Cuoco. Pic/Santa Banta 

"The few times Kaley and Ryan were out together recently, the tension was noticeable," the source told people.com. "You could tell the honeymoon phase had ended. It seemed they were trying to work out their marriage by going on dates, but they both seemed miserable."

Cuoco, 29, and Sweeting, 28, "mutually decided" to split after 21 months of marriage, her representative confirmed last week.

The actress and her husband had faced rumours of relationship trouble since April.

"Kaley and Ryan seem to have totally different personalities," the source said. "Kaley is extremely focused and high-energy. She seems to always be working. On her off time, she also keeps very busy."

But "over the summer, Ryan spent a lot of time at home," the source said. "He has been struggling with injuries and barely practiced tennis. He has acted very down."