Veteran loose forward Dixon, who has signed for Ricoh Black Rams in Japan, will be back in time for next season and has also committed for the 2020 season.
Dixon (28) has signed a one year deal with the Japanese club, and with there being no Japanese top league competition in 2019-20, due to the country hosting the Rugby World Cup, he will also be free to play for Southland in the 2019 season.
He will then play for the Highlanders in the 2020 season and, should injury not intervene, he is sure to be able pick up his 100th cap for the Highlanders.
Dixon was thrilled he could play in Japan and still stay with the Highlanders.
''It's great to get the opportunity to play a season in Japan at the end of this year. It will be a new challenge for me. I have been with the Highlanders a while now and I'm looking forward to another couple of years with them.''
Walden was believed to be heading towards the scrapheap at the start of the season, but he has made the most of the chances he has been given. He has signed on for two more years.
The 24-year-old has started in every game bar one this season and was excited to spend another two years in the south.
Highlanders chief executive Roger Clark said it was great to get players signed.
Japan was a growing attraction for players as it had a shorter season, was closer to home and players could come back the following year and play a whole season in New Zealand, thereby being available for New Zealand teams, Clark said.