The Catalan giants have been chasing the Liverpool star for months but the Reds insist he won’t be sold and have rejected every offer they’ve received.
And with the transfer deadline fast approaching, Barca are looking elsewhere in case they can’t sign the Brazilian.
Spanish publication Mundo Deportivo claim Monaco’s Lemar is on their wishlist.
News of Barca’s interest will be bittersweet to Liverpool with Jurgen Klopp also chasing the France midfielder.
Liverpool have already offered Monaco €80million (£74.4m) plus Divock Origi on loan in a final attempt to sign him.
While they could now lose out to Barca in the race for Lemar, they should at least keep Coutinho from moving to the Nou Camp.
Mundo Deportivo claim Barca have already held talks with super agent Jorge Mendes, who has close links with Monaco, to express their interest in Lemar, and are now set to begin negotiations with Monaco.
Ernesto Valverde is a long-term admirer of the 21-year-old and is drawn to his versatility with the France international able to play anywhere across the frontline and usually on the left.
Lemar registered 12 goals and 14 assists for Monaco last season as they won the French league and reached the semi-finals of the Champions League.
Lemar remains under contract with Monaco until 2020.