The crime drama was recently picked up for a thirteenth run as part of the network's 2011 fall schedule.
Greenblatt confirmed to TV Line that Jennifer Love Hewitt is in talks to appear in future episodes alongside current stars Mariska Hargitay and Christopher Meloni.
"This isn't to replace Mariska," he insisted. "The idea is that we want to bring in somebody midway through the season alongside Mariska and Chris. Mariska's deal is closed for [a thirteenth] season, so she's not disappearing. Creatively, I think it will give [her character Benson] some competition, which I think will be interesting."
He added that the addition of a new female cast member was also prompted by "what a fourteenth season might require".
"Mariska just adopted a child [and] we don't know yet if she wants to do the show for a season fourteen," he explained. "We're looking at options. Jennifer Love is somebody who we've been circling, but I don't know [if] hat is going to happen at all."
Greenblatt also suggested that introducing a new partner for Meloni's character Elliot Stabler could help to secure the show's long-term future.
"New showrunner Warren Leight is in the process of figuring all of that out," he said. "We're trying to change it up and see if some new configurations could keep the show going for several more years."
Law & Order: SVU will return to Wednesdays at 10/9c in the fall.
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