Uncapped opener Udara Jayasundera and rookie legspinner Jeffrey Vandersay have been selected in Sri Lanka's Test squad for the tour of New Zealand. The 15-man squad, which features three spinners, four quicks and eight batsmen, has no room for opener Kaushal Silva and offspinner Tharindu Kaushal.

Batsman Lahiru Thirimanne was also dropped from the squad altogether, after a being left out of Sri Lanka's most recent Test, against West Indies. Kusal Mendis, the 20-year old wicketkeeper-batsman who took Thirimanne's place in Colombo, was included again. Kithuruwan Vithanage also made a return to the Test squad, following good outings with Sri Lanka A in New Zealand last month.

Fast bowler Dushmantha Chameera featured among the quicks alongside Dhammika Prasad, Nuwan Pradeep and Suranga Lakmal. Shaminda Eranga remained injured and unavailable for selection. Rangana Herath and Dilruwan Perera were the other spinners.

Jayasundera's inclusion was expected after he hit 52 and 99 across two first-class matches against New Zealand A in Christchurch and Lincoln in October, a week after making 142 against the West Indians in a Colombo practice match. The 24-year-old has been a consistent domestic performer for Ragama Cricket Club and struck 842 runs at 64.76 in the most recent Premier League Tournament.

"Udara Jayasundera has been among the runs and has been batting very well," chief selector Kapila Wijegunawardene said. "We're just following our policy of picking players on form and giving youngsters who show potential the opportunity, whenever the situation warrants."

Vandersay, 25, had been in the selectors' sights since June, when he took a five-wicket haul against the Pakistanis in a tour match. He has since impressed in Sri Lanka's emerging team, and recently claimed two five-wicket hauls in the first-class games against New Zealand A. He was the equal-highest wicket-taker in that series with 12 scalps at an average of 24.50.

"A wristspinner brings a different dimension and lot more attacking possibilities to any side," Wijegunawardene said. "With Rangana and Dilruwan as our main, frontline spinners, we just thought Vandersay would give us another option. We do have our reasons for picking three spinners for the tour. We'll wait and see."

Silva's exclusion was perhaps the biggest surprise of the squad announcement, after he had held his place atop the batting order for almost two years. He has not consistently made runs, however, and his average is 31.90 after 44 Test innings. Silva has also had a poor recent run of form; he has only one fifty in his last 11 innings.

"Over the last few games Kaushal was not giving us the expected performances," Wijegunawardene said. "We felt that Kusal Mendis or Udara Jayasundera would be a better option. Of course we would like Kaushal to find his form and return to the side."

Silva's omission means Jayasundera is likely to open the batting alongside Dimuth Karunaratne.

Mendis was a surprise selection for an overseas tour, as he has only one first-class hundred and one fifty, after 11 matches. He made his Test debut against West Indies in Colombo, scoring 13 and 39. He will also serve as the reserve wicketkeeper to Kusal Perera on tour.

"We all saw what Kusal Mendis' capabilities were in his match in Colombo, where he was facing fast bowlers bowling at 145kph," Wijegunawardene said. "We're confident that he's got the capability. You've got to take the plunge at some point."

Sri Lanka play two Tests, in Dunedin and Hamilton. The first begins on December 10.

Test squad: Angelo Mathews (captain), Kusal Mendis, Udara Jayasundera, Dinesh Chandimal, Kusal Perera, Milinda Siriwardana, Kithuruwan Vithanage, Dimuth Karunaratne, Dhammika Prasad, Nuwan Pradeep, Suranga Lakmal, Dushmantha Chameera, Rangana Herath, Dilruwan Perera, Jeffrey Vandersay