Tom Cruise in 'Knight & Day'Have the stakes ever been this high for a movie that's not even likely to open in first or second place on the box office chart?

To hear some pundits tell it, Tom Cruise's very career as an action star may be riding on the relative success of 'Knight and Day,' even though it stands little chance of beating either last week's champ, 'Toy Story 3,' or even fellow newcomer 'Grown Ups,' starring Adam Sandler and his 'Saturday Night Live' posse. About the best 'Knight' can expect is to finish a dignified third.

Even that prospect seems iffy, however. The romantic action-comedy, which co-stars Cameron Diaz, had weak advance buzz, and though that buzz improved with last weekend's sneak previews, the reviews have been middling. The movie opened Wednesday to get a jump on the weekend competition, but its opening day pulled in just $3.8 million from about 3,100 screens. Tom Cruise in 'Knight & Day'Have the stakes ever been this high for a movie that's not even likely to open in first or second place on the box office chart?

To hear some pundits tell it, Tom Cruise's very career as an action star may be riding on the relative success of 'Knight and Day,' even though it stands little chance of beating either last week's champ, 'Toy Story 3,' or even fellow newcomer 'Grown Ups,' starring Adam Sandler and his 'Saturday Night Live' posse. About the best 'Knight' can expect is to finish a dignified third.

Even that prospect seems iffy, however. The romantic action-comedy, which co-stars Cameron Diaz, had weak advance buzz, and though that buzz improved with last weekend's sneak previews, the reviews have been middling. The movie opened Wednesday to get a jump on the weekend competition, but its opening day pulled in just $3.8 million from about 3,100 screens.

The plot -- regular gal falls for trigger-happy secret agent --sounds like a more expensive version of the early June flop 'Killers.' Plus, the movie will be competing for the same young male audience as 'Grown Ups.' Sandler still owns this audience, though Cruise has tried to reclaim it recently with his Les Grossman character from 'Tropic Thunder' and his appearance in character as that bald, booty-shaking studio chief during the recent MTV Movie Awards.

Adam Sandler and Chris Rock in 'Grown Ups'Still, the combined star power of Cruise and Diaz (herself in need of a comeback) probably won't be enough to counteract the combined star power of Sandler, Kevin James, Chris Rock, David Spade and Rob Schneider, doing the silly man-child comedy their fans have come to expect. Their movie, playing on more screens (upwards of 3,200), should easily coast to a second place victory somewhere between $32 million and $37 million, while 'Knight' will have to settle for No. 3 and a take between $24 million and $27 million from Friday to Sunday.

Meanwhile, 'Toy Story 3' should dip about 40-45 percent from last week's debut, earning another $60 to $66 million, still far and away enough for a repeat victory. Rounding out the top 5 will be 'The Karate Kid,' expected to earn another $17 million or $18 million for fourth place, and 'The A-Team' at No. 5, with another $7 million to $9 million.

Top 5 predictions:

1. 'Toy Story 3,' $64 million
2. 'Grown Ups,' $35 million
3. 'Knight and Day,' $25 million
4. 'The Karate Kid,' $18 million
5. 'The A-Team,' $8 million

•Follow Gary Susman on Twitter @garysusman.