The 22-year-old is highly regarded at Goodison Park, but has not been able to translate his youth form into senior football.
He is now the second choice goalkeeper at Blackpool, after assistant manager Steve Agnew took charge of the team.
"Harry has done well, he's made saves at crucial times for us in games, and he's a terrific young goalkeeper," Agnew said, per the Blackpool Gazette.
"In the last few games we've conceded goals; we're not saying that's all down to the goalkeeper because it's not, we made changes in the back four as well. Although we conceded two goals tonight, so we can still improve in that department; we were a threat at the top end of the pitch.
"It's always a big call because you don’t change your goalkeeper very often. Harry has fitted in the dressing room well, but we’ve got Rich's (O'Donnell) experience, and we felt we need that voice behind the back line."