The accident happened in Glasgow just hours after the former Pompey and England striker netted in Rangers' 5-0 win over Aberdeen at Ibrox.
Rangers confirmed in a tweet that Defoe had been involved in a collision, but were 'relieved' to report no serious injuries had been sustained.
The forward later let fans know that he was 'fine' yet 'a little in shock' following the accident.
In a post on his Instagram account, Defoe said: ''Thank you for all your lovely messages. I'm fine, I'm all good. 'I'm just going to go home and rest up. I'm just a little bit in shock but I'm all good.'
The ex-England ace netted 17 times in 36 appearances for Pompey having arrived from Tottenham in 2008.
Defoe joined Steven Gerrard's Gers on an 18-month loan deal from Premier League Bournemouth in January.
He has been in fine form in front of goal this season, netting nine times in 13 appearances for Rangers.