Vettel has a nine-point lead over Hamilton in the drivers' standings, and he is 23 points in front of Bottas.
Ricciardo and Verstappen, the latter a sensational maiden victor in Barcelona past year, might have to wait a little longer to make a lunge at the race lead, however, with engine supplier Renault delaying its latest power unit specification until July due to reliability concerns.
The only other driver from the leading trio of teams yet to triumph in Barcelona is Verstappen's Australian teammate, Daniel Ricciardo, but Red Bull has lagged Mercedes and Ferrari on pace so far this year.
All but three of the last 16 Spanish Grands Prix have been won from pole position.
In a season that has seen such dramatic changes to the Formula One rulebook resulting in the seesaw battle between powerhouses Mercedes and Ferrari, the freedom of development will determine who will trump who.
While Valtteri Bottas has impressed since he replaced defending champion Nico Rosberg at Mercedes - indeed he claimed the first victory of his career at the last round in Russian Federation and is just 10 points adrift of Hamilton - the Finnish driver was offered only a one-year deal after he joined from Williams.
Last year it was Dutch 18-year-old Max Verstappen who became the sport's youngest victor when he triumphed for Red Bull, on his team debut, after both Mercedes drivers collided at the start.
"I didn't get everything together, I wasn't too happy but I can feel the vehicle is quick so that is good".
"We have to wait and see what the updates will bring", Verstappen said. "They seem to know more than I do", he added.
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Wolff said Mercedes has to get used to this new scenario after dominating the series for the last three seasons.
Nico Rosberg, victor of the first four races in 2016, won the title last season with Mercedes, while Hamilton won the previous two championships.
"We're expecting some new parts, but we can't really focus too much on performance until we have solved our reliability issues", Alonso said.
"There has been a huge amount of analysis so we have definitely grown from the experience - both having a win and a fast vehicle - and a auto that struggled in so many areas".
Alonso, who will miss the Monaco Grand Prix later this month to participate at the Indianapolis 500, hitched a ride back to the pit lane on the back of a motorbike as his stricken McLaren was towed back to the garage. "It's my home race".
And it was Hamilton who held the early advantage over his team-mate.
"Bottas was quicker because he won the race but Lewis is an outstanding talent, a world champion", said the the F1 legend.
Mercedes has introduced a raft of upgrades for the first European round of the 2017 F1 season, including a more tapered nose, a re-designed shark "fin" and a "scooped duct".
"It is a better auto than what we had in Russia", Bottas said.