Symonds left his position as Marussia technical consultant last month and will start his new role as Williams technical director on August 19.
But the team is confident it will be able to operate effectively on a technical level until the right replacement becomes available.
"The key thing is that what Pat left in place with us is a very good technical structure and we have always had some very good and really talented people here," team president Graeme Lowdon told AUTOSPORT.
"The current car was a huge step forward from last year and it was the same people and structure that delivered that car who are working on the 2014 car.
"The impact on us is actually reasonably minimal because of that structure.
"There is maybe an argument it might impact the 2015 car, but we have got time to put things in place for that and we are evaluating all sorts of options at the moment."
Team principal John Booth believes that the team needs to decide whether it wants a like-for-like replacement for Symonds or appoint a more 'conceptual' technical director.
Symonds, who has worked in F1 since arriving with the Toleman team (now Lotus) in 1981, is well-regarded as a technical manager but Marussia also has the option of signing someone closer to Adrian Newey's style of getting closely involved with design work.
The work that Symonds has done in perfecting the structure since taking over technical leadership from Nick Wirth in mid-2011 means that Marussia now has a stable platform to build from.
"The first thing we need to do is identify the type of person we are looking for; organisational/managerial-led like Pat or a technical director with a design strength or aero background" Booth told AUTOSPORT.
"It could be an opportunity for us to take the next step from where we are because the structure is in place now.
"The first thing is to make sure there is no interruption to the 2014 car and we are pretty happy with that.
"And we have to get the Ferrari relationship working flat out, which it is now, so we can take a breath and look at where we are going."
Lowdon admitted that it was no surprise Symonds was in demand among other teams.
Because Symonds was engaged as a consultant, his notice period is shorter than that of the typical technical director.
"It was pretty short notice, but as a management team you have to be ready to react to things and have various scenarios in your mind anyway.
"I'm sure a lot of teams would have been interested in Pat's services but he was given an opportunity at Williams that looks very attractive to him and we wish him the best of luck.
"Pat is a racer and is going to take an opportunity like that and see where it gets him so it's up to us to race against him now."
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- Graeme Lowdon