21 Dec, 18:00
England international Defoe was forced off with an ankle injury following a mistimed tackle from Chelsea's Ethan Ampadu early in the game while Arter was substituted in the second half with a calf problem.
The duo joins several players, including Joshua King, Charlie Daniels and Tyrone Mings on the sidelines for Bournemouth and Howe is worried about his depleted squad ahead of a packed festive schedule.
-It looks like he has potentially got some damage to his ankle ligaments. It was a nasty tackle. He went over on his ankle, he wasn't right, he had to come off.But it meant we lost Jermaine and that is going to be a huge blow to us. Harry Arter felt his calf and had to come off so we really are stretched. We have a number of players back home who are injured so we hope none of them is too serious, Howe said.
Bournemouth is 16th in the Premier League and played four matches in the space of 10 days, starting with Saturday's trip to leaders Manchester City and ending with a New Year's day clash at Brighton and Hove Albion.