David De Gea
David De Gea will be share first team duties with Iker Casillas for Spain.Getty

Vicente del Bosque will not hand David de Gea a starting spot in the Spain side immediately, planning to instead rotate the Manchester United shot stopper with Iker Casillas to ensure a 'smooth transition' in the national side.

Casillas has captained La Roja for the past eight years but his position in the first team came under severe scrutiny following a dismal World Cup campaign in Brazil.

Del Bosque came under further pressure to drop the long-serving goalkeeper following another error in Spain's European Championship qualifier defeat to Slovakia in early October.

Following his sensational club form, De Gea won his first competitive international cap when he was given the nod for Spains' next qualifier against Luxembourg.

De Gea is seen as Casillas' long-term heir but the Spain manager insists the two will continue to share first-team duties for the remainder of the qualifying campaign.

"I have repeatedly said that the transition must be smooth," Del Bosque was quoted as saying by AS. "Casillas is an institution in Spanish football and he wishes to play until at least Euro 2016 in France.

"We have him here because he is so influential in the team and if he was not playing then the decision would have been tougher.

"It would have been the same for De Gea if he was not playing for Manchester United."

Spain have taken six points from a possible nine from their opening three qualifiers, leaving them second behind Group C leaders Slovakia, who have won all three games so far.

Del Bosque's side continue their campaign at home to Belarus on Saturday before taking on world champions Germany in a friendly on Tuesday.