Carra made his 700th appearance for Liverpool in the Europa League win at FC Gomel this week.
Callaghan, who played 857 times for the Reds, told liverpoolfc.com: "Jamie would have to play 50 games a season for another three seasons to get there, which is a lot to ask, but at the end of the day records are there to be broken.
"And I have said all along that if anyone was going to break it I'd like it to be Jamie because he's a lovely guy, a fantastic footballer and has a great attitude.
"But even if he doesn't get there, to reach 700 games is a fantastic milestone, especially in this age of squad rotation.
"When I was playing it was the age of Shanks telling us 'Same team as last season', so it's fantastic for Jamie to get to 700."