Barcelona centre-back Pique misses out after suffering a foot injury in last month's Champions League win over Spartak Moscow that he is still recovering from.
Bayern Munich new boy Martinez, who can play in defence or midfield, returns after being omitted from the Spain squad for their opening qualifier against Georgia.
Chelsea midfielder Juan Mata is still absent, as is his fellow Euro 2012 winner Alvaro Negredo.
Mata's exclusion from the previous squad came following a request from Chelsea to reduce his workload after a busy summer which saw the 24-year-old represent Spain at both the European Championship and the London Olympics, alongside Martinez .
Spain beat Georgia 1-0 in Tbilisi and are currently second in Group I behind France, who have six points having played a game more.
The reigning world and European champions play Belarus in Minsk next Friday and the French in Madrid four days later.
Also missing again is Barca centre-back Carles Puyol.
Puyol dislocated his elbow in this week's Champions League victory over Benfica and is set to be out for eight weeks.
That means the 34-year-old, who also missed Euro 2012 with a knee injury, will again have to wait to try and reach 100 caps for his country having been stuck on 99 since February.
Del Bosque said: "I've not spoken with Puyol, I've only sent him a message of support. It's a shame. His presence alone in the national team is very important but he's had bad luck and we all wish him a quick recovery and that he can reach 100 games."
Puyol will definitely miss this weekend's El Clasico showdown with Real Madrid, and it remains to be seen if Pique plays any part in that match.
The absence of the two Barca centre-backs is a blow to Spain, but Del Bosque believes Martinez offers useful options to either play at the back or further forward.
He said: "With Javi Martinez we have two alternatives. I've named him in the list as a defender but that doesn't mean anything.
"We will use him where we think it's best."
He added: "I don't know if Pique will play on Sunday but he still hasn't trained and we don't think it's right to call him up.
"We've brought in those we who think are the best at this moment, but of course there are other centre-backs who could have come in: (Alvaro) Dominguez, Victor Ruiz, those from the under-21s..."
Regarding the absence of Mata, who scored twice for Chelsea in their Champions League win over Nordsjaelland on Tuesday and the winner in last weekend's 2-1 league win at Arsenal, Del Bosque said: "We have a problem with quantity, not quality.
"It pains me to leave out some of those who haven't been called up, because there are others who could have been here.
"He wasn't in the previous list because we agreed with Chelsea that he had to have a break which he didn't have in the summer. But we haven't any space to bring him in this time."
Spain squad to play Belarus on October 12 and France on October 16:
Iker Casillas (Real Madrid), Victor Valdes (Barcelona), Jose Reina (Liverpool); Alvaro Arbeloa (Real Madrid), Sergio Ramos (Real Madrid), Raul Albiol (Real Madrid), Jordi Alba (Barcelona), Nacho Monreal (Malaga), Juanfran Torres (Atletico Madrid); Xabi Alonso (Real Madrid), Sergio Busquets (Barcelona), Xavi (Barcelona), Andres Iniesta (Barcelona), Javi Martinez (Bayern Munich), Cesc Fabregas (Barcelona), David Silva (Manchester City), Benat Etxebarria (Real Betis), Santi Cazorla (Arsenal), Pedro Rodriguez (Barcelona), Jesus Navas (Sevilla); Fernando Torres (Chelsea), David Villa (Barcelona), Roberto Soldado (Valencia).