Yeoman hinted that fans of the show will recognise the object of Rigsby's affection when she appears in a future episode.
"There will be a new love interest brewing for my character," he told TV Guide. "Likely someone we saw Rigsby strike up a flirtation with in seasons past."
Yeoman teased that one of the possible characters is Sara (Jillian Bach), who Rigsby met in the last season.
"We had this funny interrogation scene and then she asked me out on a little date," he said. "I loved working with her and people reacted favourably."
Yeoman recently admitted that he expects the Red John storyline to continue when The Mentalist returns for its fourth season on CBS on September 22.
> Reed Diamond lands 'The Mentalist' role
Watch a clip from the third season finale of The Mentalist below: