It had run out at the end of May but it will now resume until Portsmouth's final match of the campaign.
Although there remains uncertainty about whether League One will continue, the EFL have indicated that if clubs do vote to end the regular season next week the Play-Offs will still go ahead.
Pompey are currently fourth in the table and have made clear that they want to play on regardless.
Left-back of left wing-back Seddon has impressed down at Fratton Park.
After joining on a Standard Loan in January, he has made 17 appearances and chipped in with one goal.
Seddon made his senior debut for Blues on the opening day of the season and added four more appearances before it was decided to go down the loan route to gain more valuable competitive experience.