Portsmouth have handed trials to former Chelsea defender Jon Harley and ex-Doncaster full-back Mustapha Dumbaya.
Harley, who was released by Notts County at the end of last season, and Dumbaya have linked up with the rest of Pompey's squad for pre-season training, although the personnel will have changed significantly by the time the League One campaign begins.
The eight senior players who returned to training - Tal Ben Haim, Greg Halford, Erik Huseklepp, Dave Kitson, Liam Lawrence, Hayden Mullins, David Norris and Luke Varney - all need to be sold to cut costs at Fratton Park.
Veteran striker Kanu was absent along with defender Aaron Mokoena, who is understood to be close to returning to South Africa and joining Bidvest Wits.
Manager Michael Appleton told Pompey's website: "Coming in for the first day of training with just eight senior players is a new experience for me. I was expecting 10 senior players, so there were a couple of absentees. But the lads who came in are in reasonable shape and did great.
"When the players do leave I might get the opportunity to sign someone. We're still in the same situation - bodies need to leave the building. It's going to be a pre-season to remember, although probably not one I'll remember fondly."