Pompey have signed goalkeeper Phil Smith on a one-month deal.
The 32-year-old has been a free agent since leaving Swindon in the summer. He will wear the number one shirt and is eligible to play at Tranmere on Saturday.
Caretaker Blues boss Guy Whittingham said: "He's trained with us this week and looked good considering he hasn't done much since the summer.
"We've brought him in because of the vast amount of experience he can offer us. He's also got a great work ethic and has a desire to do well."
Smith made a total of 132 appearances during his six years with the Robins after arriving from Crawley in 2006.
Simon Eastwood had been the only other senior goalkeeper in Pompey’s squad following Oldham’s decision to recall Alex Cisak from his loan spell last week.