Depending on his age- all Puppies under 8 weeks should not be separated by their mother.
If a Puppy whines and paces, he is still looking for his mother- this is how most of Puppies get used to the separation anxiety:
If you have an old wind up Alarm Clock with a tick-tock sound or buy one if you have to and put it with the Puppy in his basket, the Puppy will take the tick tock sound as his missing mothers heart beat and will get used to being alone.
Also, find a designated Area either in the Bedroom next to the Bed or in an specific corner or Place, so the Puppie early on knows "where his or hers Spot" is!
Walk the Puppy one more time before going to bed, especially Puppies should get a regularity and it will help them "ween" off!
Put all Foods up, when done Feeding - Dogs should be really only eating one full Bowl per Day, every time the Dog is done eating, put the Food up.
Almost like we eat- Breakfast, Lunch and Dinner Bowl down- Feeding done- Bowl up and only water should be out at all times.
But I really hope the Trick with the Alarm clock works...the sound of the Clock (tick tock) resembles the heartbeat of the mother. It will soothe the Puppy and hopefully he will calm down. Worked with all my Dogs!
Good luck and fun with the Puppy! And lots of Love...Dogs are great for the soul and our wellbeing!