(REUTERS) - Williams will take their time in announcing Brazilian Felipe Massa's replacement for next season, the Formula One team's technical head Paddy Lowe said on Friday (Nov 10).

Massa, 36, announced ahead of his home Grand Prix at Interlagos this weekend that he is leaving Formula One at the end of the year.

Williams have tested Poland's Robert Kubica and Britain's Paul di Resta, both older drivers seeking a comeback after years out, but also have 23-year-old German Pascal Wehrlein and Russian Daniil Kvyat on the list.

"We're very unlikely to make a decision in short order," Lowe, who joined from champions Mercedes earlier in the year, told reporters.

"We have a number of different options and we'll take our time with that and let you know when we have an answer," he added.

Former champions Williams have 19-year-old Canadian Lance Stroll as their other driver.

The Mercedes-powered team are currently fifth in the constructors' standings, with fourth now a mathematical impossibility.

"We are motivated to make some significant change to really move forward and create a step from where we are," said Lowe of plans for 2018.

"We're quite optimistic about what we're doing over the winter."