Barath suffered a hamstring injury during the first ODI in Mirpur and played no further part in the three-match series, which West Indies won 2-1. He will remain with the team in Bangladesh and continue his rehabilitation.
Simmons was in impressive form during the limited-overs leg of the tour, scoring 202 runs in two ODIs and 23 in the Twenty20. He did not play the final ODI in Chittagong because of a minor back problem.
He was in the side for the two home Tests against Pakistan in May, and started the Test series against India as well before being dropped for the third match. Simmons averages 16.21 in the seven Tests he has played but says this opportunity comes at the right time since he is in form
"I'm playing very well and feeling quite comfortable and confident," he said. "I had a good ODI Series so the aim is to kick on and get some big scores in the Test Series as well. This is a chance for me to put everything right and look to cement a spot. It's a matter of concentrating hard. When I get a start I know I have to look to build on that. I have made some big scores at first-class level so I know that in the long version of the game you have to be patient and build a foundation."
During the ODI in Chittagong, West Indies' batsmen were found wanting on a turning pitch and were bowled out for 61. The first Test will be at the same venue, beginning October 21, and Simmons said he was ready for the challenge the pitch would pose.
"Watching the pitch here in Chittagong, it is quite different to the ones we played on in Dhaka. In Dhaka you were able to play your shots a lot more freely. The one here was quite slow and the ball was gripping a bit on the surface. On this pitch you have to be very watchful and patient. The key is to get a start and once you get in you can't give it away. That will be my focus."
Squad: Darren Sammy (capt), Carlton Baugh, Devendra Bishoo, Kraigg Brathwaite, Darren Bravo, Shivnarine Chanderpaul, Fidel Edwards, Kirk Edwards, Kieran Powell, Denesh Ramdin, Ravi Rampaul, Kemar Roach, Marlon Samuels, Shane Shillingford, Lendl Simmons.