The Brazilian forward has been linked with a return to Camp Nou, three years on from joining PSG for a record fee of £198m.
Neymar won eight major trophies during a four-season stay at Barca and is rumoured to have come close to moving back to Catalonia last year.
However, as the coronavirus pandemic continues to financially cripple clubs, Bartomeu admits that it would be tough to pull off a transfer in the current climate.
"Such an operation is unlikely because the situation of all the clubs in Europe is very difficult," Bartomeu told RAC1.
Neymar has scored 69 goals in 80 appearances for PSG since joining in August 2017.