The Buffs head into Saturday's game 4-4, while Texas Tech is 6-2, its two losses coming on the road against Big 12 foes Oklahoma State and Missouri.
Crabtree's emergence has been a surprise to those outside Lubbock.
"He's just good," senior Terrence Wheatley said about Crabtree. "He's big, fast, strong. For a freshman (to be that good), it's almost not fair.
"He's competitive. I haven't seen him back down from anybody."
Wheatley added that Crabtree, at 6-3, 208 pounds, is the kind of receiver that tries to run over defenders when he catches the ball. But CU can't focus its defensive efforts on Crabtree. Nine Red Raiders have caught double digit passes, including senior Danny Amendola, who has 71 receptions.
Harrell, meanwhile, has been impressive, too.
"He knows everything — he knows where all his receivers are going to be," Wheatley said.
Even though Crabtree is a new addition, CU will be facing a similar team that it faced in Boulder last season. Same quarterback, same Mike Leach spread offense. Colorado won that game 30-6, holding the high powered Red Raider offense well under its average of 32.5 points a game.
In that game, CU sacked Harrell twice, and hounded him several other times. Wheatley said on Tuesday, the Buffs' defenders felt like they were able to get into Harrell's head in the 2006 game. CU intercepted Harrell three times that game. (He's thrown just seven picks in 416 pass attempts this season).
When facing TTU, the question always becomes — do you blitz and try and force mistakes (and risk getting burned) or do you sit back in coverage and force receivers to make plays (and risk getting picked apart).
Colorado was able to find a good balance in last season's game. They'll probably try and do the same this time around. But don't expect the exact same defensive looks, Wheatley said.
"(Last year's win) gives us an idea of what we can do," he said, adding that they probably couldn't get away with doing the same thing.