Mendis endured a modest Test series against Pakistan, in which his contributions were 10, 18, 1 and 29. Although he made an excellent century against India in August, he had only crossed fifty in two of his last 14 innings.
Mendis' omission from the squad has caused some consternation, especially as he has been repeatedly talked up by coaches and management as the batsman on whom the top order might hinge in coming years. Earlier in the year, against Bangladesh, Mendis' 194 also turned out to be a match-winning innings.
However, according to chief selector Graeme Labrooy, it is precisely because the selectors are mindful of Mendis' potential, that they left him out of the squad.
"We don't want a situation where he plays two more innings, gets two low scores and then drop him and destroy his confidence further," he told The Island. "He has got age on his side and we want him to go on to become one of the greats of the game. We want him to play for another ten years."
Not only were Sri Lanka comfortably whitewashed by India in the three-Test series in July and August, they have also struggled in India historically, having never won a Test there. The tour is likely to challenge even the most experienced Sri Lanka batsmen, with India's bowlers in outstanding form at home.
"We didn't want to throw him to the deep end or take him to India and leave him on the bench," Labrooy said. "What we tried to do was to let him play some domestic cricket, work on his game and regain his confidence. He is a confidence player. For him confidence is everything, and he has got everything in his armoury."
That Lahiru Thirimanne was preferred to Mendis has been a particular bone of contention, given Thirimanne's very modest Test record. He averages 23.1 across 52 Test innings, and has crossed fifty only five times in his career.
However, while Thirimanne has been picked in the squad, his place in the top order is not completely assured. Dhananjaya de Silva, who has returned to form with scores of 104, 73 and 64 for Sri Lanka A on the West Indies tour, could enter the top order. Though de Silva had made a successful entry into Test cricket from the lower middle order, it is as an opener that he regularly plays for his domestic club side, Tamil Union.
"The No.3 position is a toss up between Thirimanne and Dhananjaya," Labrooy said. "We are glad that Dhananjaya made some runs for Sri Lanka A in the Caribbean. He will be considered as an opener or No. 3 batsman in the future and we don't want to drop him to the middle order."
With Kaushal Silva - who opened unsuccessfully for Sri Lanka in the UAE - left out of the squad to India, de Silva and 22-year-old batsman Sadeera Samarawickrama become the primary candidates to open the innings alongside Dimuth Karunaratne. Samarawickrama is often a middle-order batsman and wicketkeeper in first-class cricket, but does open the innings in limited-overs cricket for his club side.
He had showcased substantial attacking flair in his maiden Test innings in Abu Dhabi, and it is the style and rate of his run-making that appears to have struck the selectors.
"Sadeera is a player for the future. This is the correct time that we should bring him in. Now is the time for him to bite the bullet and take up that challenge against world's number one ranked team. He will put pressure back on the bowlers by putting the loose balls away. We are very impressed with his game."