Paris Saint-Germain coach Laurent Blanc concedes it may be difficult to convince Mamadou Sakho that he should remain at the club.
The 23-year-old defender is a Paris native who has graduated out of PSG's academy system to become a senior France international.
He is, however, no longer guaranteed first-team football, with an ambitious project at Parc des Princes having increased competition for places.
Sakho feels he needs to be playing regularly if he is to remain part of the international set-up and has hinted at a summer move away from PSG.
Liverpool and Monaco are among those reported to be keen, and could be ready to test PSG's resolve.
Blanc would rather not part with a player of such promise, but appreciates that Sakho may decide to take on a new challenge.
He told L'Equipe: "When a player wants to change his club you have to offer an argument that makes him want to stay.
"You also have to look at what his status is in the team. If that status won't change, what can you say?"
The 32-year-old returns to England after three seasons in Scotland with St Johnstone, Queen of the South and St Mirren, who won the Scottish League Cup last season.
Parkin said: "Exeter were looking to bring in a front player and fortunately after having a meeting with the manager and a really good chat, I've been down to have a look at the place and I'm really delighted to have signed.
"I know that Exeter have got a tradition of playing good football and the manager has obviously got a great reputation, so it was a no-brainer really.
"I'm just delighted to get another opportunity down here to play football and hopefully be part of a successful team."
Parkin started out at Chelsea, had a prolific spell at Swindon and went on to play for Ipswich, Luton and Walsall before heading north of the border.
