"It's an exciting time for the whole squad and particularly the three players making their returns," Sawyer said.
"We've seen the success Jess has enjoyed on the international stage in her career to date and it's been encouraging to see her working her way back from injury, and training with the London Spirit over here in the Hundred in recent weeks.
"It's great to see Lauren return after taking some personal time away from the game. She was flying with the bat heading into the ODI World Cup in New Zealand earlier this year only to be ruled out of the tournament with that thumb injury - so we're looking forward to welcoming her back into the environment.
"I first saw Molly bowling when I was working with Australia at the ODI World Cup and remember telling them how good I thought she was, just from watching her practice. You could see she had all the natural attributes for fast bowling and I've been sent a few videos of her recent progress - she seems to be going really well."
Canterbury all-rounder Lea Tahuhu has retained her place in the squad after impressing as a replacement for Kerr at the Commonwealth Games.
The squad sees the retention of the four youngsters who featured in Birmingham: wicketkeeper Izzy Gaze (18), Wellington batter Georgia Plimmer (18), Auckland left-arm spinner Fran Jonas (18), and Otago off-spinner Eden Carson (21).
Sophie Devine will captain the side which also features the familiar faces of Suzie Bates, Maddy Green and Melie Kerr.
Sawyer, who's been working with Devine at the Birmingham Phoenix in the Hundred, said the squad for the West Indies were undergoing a variety of preparations ahead of the tour.
"We have six players currently competing over here in the Hundred, while the bulk of the squad has begun a training camp this week at Lincoln, working with assistant coach Sara McGlashan.
"Hayley Jensen is already over in the Caribbean playing in the CPL and she said the conditions are extremely hot and the wickets are keeping a little low - so that's what we can expect."
With the T20 World Cup to be held in South Africa next February, Sawyer said the side would be working towards that tournament, and looking to take momentum from their recent success in Birmingham.
"I know the team took a lot of confidence from winning that bronze-medal match against England," he said.
"To do it in front of a packed house at Edgbaston and to do it so convincingly will have given the whole unit so much belief.
"This tour will be important for us to continue building on the good work done in England."
The White Ferns last toured West Indies in 2014, when they lost the ODI series 4-0, but managed to edge the T20Is 2-1 following a thrilling Super Over victory in the deciding match.
White Ferns squad for West Indies tour
Sophie Devine (c), Suzie Bates, Eden Carson, Lauren Down, Izzy Gaze, Maddy Green, Brooke Halliday, Hayley Jensen, Fran Jonas, Jess Kerr, Melie Kerr, Molly Penfold, Georgia Plimmer, Hannah Rowe, Lea Tahuhu.
