The first two pieces of Terry Collins’ Mets coaching staff are complete: Dan Warthen will remain as pitching coach and Chip Hale as third-base coach, league sources told The Post on Monday.

Hale, who lost out to Collins in the managerial search, was expected back but there was some uncertainty whether Warthen would return because of Collins’ close relationship with former Mets pitching coach Dave Wallace.

According to a team source, Howard Johnson has not been told if he’ll be retained as hitting coach. There are still vacancies at bench coach and first-base coach. Triple-A manager Ken Oberkfell is a candidate for bench coach and Mookie Wilson could coach first base.