TORONTO — Dellin Betances is joining the Yankees on Sunday and Aaron Boone’s hope is the right-handed reliever can build enough arm strength over the next two weeks to possibly help in the postseason.

Betances completed a rehab assignment Friday night pitching for Double-A Trenton when the Thunder beat Bowie for the Eastern League title. In his third minor league game, Betances worked an inning, gave up two hits (one homer), a run and struck out one.

Betances never made it out of spring training due to an impingement in his right shoulder. While rehabbing that he suffered a lat injury. Those injuries combined to keep the 31-year-old out of the big leagues all season.

When healthy, Betances pushes speed guns near triple digits, but don’t look for that immediately since his minor league velocity has been in the 94-95 mph range. Boone said it was 92-94 Friday night.

Asked if he would use Betances in the late innings, a role in which he has dominated for the past five seasons, Boone said he wasn’t sure.

“I don’t know, we will see. We will manage him as far as being smart about his work load and building him up properly,’’ said Boone, who also wasn’t sure if Betances would pitch Sunday. “Getting him in spots where he can be successful. Whether that falls into the back end I am not sure. We will see [Sunday]. I am not certain he will pitch [Sunday]. It would be the first time pitching after one day’s rest. There may be a situation we might want to throw him in. The biggest thing is trying to get him built up properly.’’

As far as Betances’ velocity, Boone would like to see it rise.

“I am hoping it will tick up,’’ Boone said before the Yankees’ 13-3 blowout win over the Blue Jays on Saturday. “I don’t worry that much about it. I am more worried about making sure he is staying in his delivery and the crispness and the sharpness of his breaking balls. As he continues to get regular work hopefully we will start to see the fastball velocity tick up.’’