The former Posh left back came to Crewe as a trialist and has trained at the Heath for the last few weeks.
22-year-old Blanchett has featured in the all three pre-season games (Kidsgrove Athletic, Lancaster City and WBA) his performances have been solid which has prompted manager Dario Gradi to offer the Harrow born defender a contract.
Gradi told Radio Stoke "I quite like him and we'll have a talk about it now because we have some other possibilities"
Meanwhile former trialist Chris Stokes is training with League One side Walsall and featured in their pre-season defeat to Wolves. 19-year-old Stokes had a brief loan spell at Gresty Road last season before injury cut it short.