LOS ANGELES (thefutoncritic.com) -- "Who would have thought that "C.S.I." would be the underdog?" CBS Entertainment Nina Tassler told reporters during the network's executive session of the TCA Summer Press Tour on Saturday.

"We expect to be dinged a little bit by "Grey's [Anatomy]." It's going to be very competitive. But as we know from the past, two big hit shows or more can occupy the same time period," she added about the upcoming Thursday, 9:00/8:00c showdown between the two series this fall. "We are going to be very aggressive in terms of strategizing with the show this year, [and its] story lines. There's some interesting creative casting ideas going on now. So we will be incredibly competitive, but we do expect to get dinged."

When pressed for specifics about the new season, Tassler said: "We are going to see more of Grissom and Sara, which was a huge... was hugely embraced by the audience last year. You will definitely see that relationship evolve." She was also quick to note their storyline isn't being played up or down because of the more relationship-based "Grey's" - "We've been sort of teasing that during most of the year last year. And then the finale, which we just got a tremendous response from the audience, tremendous response."

This past season "C.S.I." averaged a massive 25.2 million viewers on Thursday nights while "Grey's Anatomy" averaged 19.9 million on Sundays. Said competition forced NBC to pull its much-hyped new drama "Studio 60 on the Sunset Strip" from the slot, a decision Tassler says they "were not surprised by."

"C.S.I." however wasn't the only show on reporters' minds. When asked about the sudden growth of serialized dramas (such as "Smith" and "Jericho"), Tassler shot back: "It's so funny. Just last year we talked about, "Are you going to put more crime dramas on? We've had enough with the crime dramas." Now we've got serialized dramas. You've got something different. It's like, "Oh, my God, it's enough with the serialized dramas."

Tassler went on to say they don't pick and choose their shows based on format: "It's not like that. It's really, first and foremost, what's the story you're telling and what best facilitates communicating that story to the audience. That's it."

She also defended the network's time slot changes, such as sending "The Amazing Race" and "Without a Trace" to Sundays and flip-flopping the previously announced Monday combo of "The Class" and "How I Met Your Mother."

"We saw this as a great opportunity for "Trace." It's a top-ten show. It performs very well. We also saw an opportunity to really improve overall on Sunday night," Tassler said about the former. "And moving "Race" there gave us an opportunity to really sort of start the night off. "Trace" -- I'm sorry, "Race" is a self-starter. And we really saw, just overall, a way to build up Sunday. "Trace" was ready to move."

As for the latter change, she added: "The shows, both of them are very compatible, and we really saw is it as an opportunity to open the night big with "The Class." It's really now the one change we're making on Monday night. It was a decision to keep "How I Met Your Mother" in its time period and just let it bask in the halo of the promo from "The Class." But it was just a decision we made that gave "How I Met Your Mother" to continue to perform in its time period."

Among other tidbits: while its Sunday movie isn't returning as a regular component of its schedule, there still will be "big-event programming" as well as several Hallmark-produced originals; the small-screen remake of "Network" remains on track however is being hampered by producer George Clooney's feature commitments; the midseason animated series "Creature Comforts" is still moving forward (despite its absence from the network's upfront materials); and telenovelas are still a possibility for next summer however they're still working on a business model.