Martin Samuelsen hopes to prove himself to West Ham boss Slaven Bilic.
The Norway winger spent last term on-loan at Peterborough United.
He told whufc.com: “I'm very excited and glad to be back. I had a nice holiday and I'm raring to go. It's nice to have fresh kit and everything and I'm really looking forward to training again.
“Every time I train, it's a chance to show what I can do. I'm just going to give it my all and hope for the best.
“I'll know more about my aims for the season when this pre-season is done. My main focus is just to do as best as I can this pre-season."