The 36-year-old goalkeeper has been without a club since last summer since being released by Aberdeen.
A highly experienced goalkeeper, Lewis has extensive experience of playing in Scotland and England and is still keen to continue his career.
His representatives have been looking to find a new club as the winter transfer window approaches.
Lewis is now training at the Manchester United academy to keep his fitness levels up.
He has been granted the opportunity to work with the Manchester United academy staff in order to remain sharp.
He is hopeful of getting a new club given his experience in the winter window and is keen to remain fit for an opportunity.
It remains to be seen whether a club take a punt on Lewis in the winter window if they need an emergency signing in the goalkeeping department.
He made more than 200 Scottish top-flight appearances and has made close to 100 appearances in the Championship in England.
