The 22-year-old stresses he is determined to convince the club hierarchy they do not need to invest in another defender following his brief showing against Ajax
The Catalans saw efforts to sign the likes of Thiago Silva and David Luiz fail this summer after allowing Eric Abidal to join Monaco, leaving the Blaugrana light in defensive depth heading into the 2013-14 campaign.
However, Bartra - who made a brief appearance in the Champions League win over Ajax on Wednesday - has vowed to repay the faith afforded him by Martino as he looks to cement his place in the first-team squad thiss eason.
"I was very eagar to play and grateful to get minutes at Camp Nou," the Spain Under-21 international told Mundo Deportivo following his cameo in the 4-0 thrashing of Ajax.
"I have to prove everything and I will try to show that there is no need to sign a centre-back."
The 22-year-old has made 25 senior appearances for the Blaugrana to date, scoring one goal.