The government says its tough austerity measures have started to strengthen the economy, which officially emerged from recession in 2013 and grew an estimated 1.4 percent in 2014.
For 2015, "we are conscious that our current forecast of two percent is lower than the market consensus," the newspaper Expansion quoted Economy Minister Luis de Guindos as saying.
That forecast was calculated before the recent plunge in oil prices and a decline of the euro against the dollar, which can give Spain's domestic activity and exports a boost.
"If the oil price and the exchange rate stay at these levels, we will have additional growth of 0.5 percentage points, and that is a cautious estimate," Guindos said.
The government is due to release its updated official forecasts in April.
The euro traded at about $1.25 in mid-December but was down to $1.12 on Monday.
Crude oil prices have tumbled about 60 percent since June 2014, below the key $50 per barrel mark.