fender telecaster strings

Guitar String Gauges?
I play a fender telecaster and usually play with 9 gauge or 10 gauge. Today I went into the guitar shop and bought 11′s. The worker said it could ruin my whole neck if I put 11′s on because before, I played with9′s or 10′s. What will happen?
The heavier strings will put more upward pull on the neck, but it should not ruin it. You might have to adjust the truss rod and reset the intonation, but I know a lot of people who play 11′s on a telecaster. You should probably take it in and get it set up right for the 11′s though.
Fender Telecaster: Electric Guitar Setup : Guitar String Action: Fender Telecaster