Oxford have completed the signing of experienced goalkeeper Jamie Ashdown on a deal until the end of the season.
He left Crawley in November and was available as a free agent, meaning the U's did not have to complete his signing during the transfer window.
Ashdown, 34, has played for Portsmouth, Reading, Ebbsfleet, Norwich, Leeds, Bournemouth and Rushden & Diamonds.
"We want competition all through the squad so he'll push Ryan Clarke in goal," said boss Michael Appleton.
"At the same time Max Crocombe has been very patient but needs to play games, so Jamie being here may well allow Max to go out on loan and gain experience.
"All three of them are very good goalkeepers and strong characters and I think we now have very healthy competition in that position."
Ashdown, who collected an FA Cup winner's medal as part of Portsmouth matchday squad in the 2008 final at Wembley, added: "I'm really happy to have joined.
"I had the opportunity to play abroad but this is a great opportunity for me and I'm looking forward to it.
"I still have that enthusiasm and work ethic and can't wait to get out there diving about in training and joining in. It's a good club, very ambitious, and an exciting new challenge for me."