When Elisa first appears, she hires Parker to represent her in a case against a company that was withholding money to help pay pay for her father's medical bills. Later, she was represented by Jane and had to eventually turn in her nursing license because she had gone illegally to Canada to buy the pills for her father. She gave in an application to start nursing again, and while she was waiting for a decision from the medical board, Parker hires her as an assistant which makes Kim jealous. This results in Kim making Elisa stay late at the office. When Parker finds out, he tells her that Elisa answers only to him. Later it is revealed the Parker still has feelings for Elisa. Later it is revealed that Elisa has a son named Eric. Jane finds out that he is Parker's son and Elisa asks her to keep the child a secret from him. But Parker still learned the truth after he went to the hospital to see Elisa, and was angry at her because she hid this secret from him. This made Elisa quit the firm and move back to Chicago with Eric. Later, Kim convinces Parker to go after Elisa and their son.
Elisa returns when Eric disobeyes her and comes to see Parker at the firm. She stays in the city for a while, until she finally decides to go to Canada where she can nurse again, instead of staying in the US where her licence is still pending. Parker doesn't want her and Eric to go, and with the help of Kim forces Elisa to court to get the custody of their son. This hurts their already fragile friendship even more, and they end up argueing in court and accusing each other. Eventually, Elisa gets full custody of Eric and moves away to Canada, telling Parker before she leaves that she doesn't want to have anything to do with him anymore.
After Kim tells Parker she's pregnant, he travels to Canada to be with Elisa and Eric, and hasn't been present on the show since.