... it seems he will only be involved in Saturday's game with Fulham at St James' Park if Shola Ameobi fails a fitness test.
The Manchester United striker is on loan until January 1, but it is thought Glenn Roeder wants to go with a strike force of Martins and Ameobi.
Roeder: "Seppe has been away with the Italian Under-21 squad this week and been involved in the two games with Iceland and Austria.
"He has since been back to Manchester to pick up his gear, but he is here now and he will train with us today and tomorrow. We will get to know him and he will get to know us, and then we will decide about Saturday.
"Although he never said anything directly to me, I know that Sir Alex Ferguson trusts me to look after the boy - and don't forget he is still only 19. He is not an experienced 25 or 26-year-old, and at 19 I do not intend to put him under any sort of pressure he does not need.
"I knew what I was doing when I brought Jermain Defoe through at West Ham and he has developed into an England striker. But at the same time I have seen far too many young players burn themselves out because of over-use - and that has resulted in them picking up injuries, so I will use Seppe sensibly."