Sinthaweechai also won Kor Royal Cup with the club in the next season, but failed to protect their league title from PEA.

Anyway, under the management of Winfried Schafer, which was appointed as Thailand's head coach in July, 2011, Sinthaweechai firmly regained his first team regular in Thailand national team so far, especially in 2014 Asian World Cup Qualifying section which he earned many positive comments from the media and fans regarded to his performances against Australia.

In 2013, he was called up to the national team by Surachai Jaturapattarapong to the 2015 AFC Asian Cup qualification, he was chosen by the coach as captain.

On 5 September 2017, Sinthaweechai announced his early retirement from international football after the match with Australia in 2018 FIFA World Cup qualification – AFC third round.

[7] On 14 October 2018, Football Association of Thailand organised Sinthaweechai Testimonial Match with Trinidad and Tobago national football team at Suphan Buri Provincial Stadium, as part of FIFA Friendly schedule and ended with score 1–0 win for the Thais over Trinidad and Tobago, ending his national career covering 14 years and 79 match appearances.

[8][9][10] Sinthaweechai is known as a sweeper keeper because of his speed when he rushes off his line to anticipate opponents who have beaten the offside trap.