Tampines travel to Hanoi for their third match of the ongoing tournament on Wednesday.
Lee says he is in no mood to retire and might even continue till the 2020 Tokyo Olympics.
Sundram along with technical director Michael Sablon have been given contract extensions.
JDT host the Philippines club in clash of table-toppers on Tuesday.
Home host Vietnam's Than Quang Ninh at the Jalan Besar Stadium on Tuesday.
The second seed takes on 31st seed Del Potro in third-round match on Tuesday.
Kohlschreiber has never beaten the Swiss star in their four meetings so far.
Lee defeated China's Shi Yuqi in the final on Sunday to clinch his fourth title.
Chelsea face Manchester United in the FA Cup clash on Monday.
Federer is favourite to win his second-round clash against the world number 80.
Tottenham Hotspur face Millwall in the FA Cup clash on Sunday.
Djokovic begins title defence at Indian Wells on Sunday.
Angela Lee retains One Women's Atomweight World Championship with Tko over Jenny Huang
Liverpool face Burnley in the Premier League clash on Sunday.
World number one Tai faces in-form Intanon in the title match on Sunday.