The UEFA Europa League semi-finalists head into their league final against Celta Vigo on Saturday knowing a win could see them finish as high as eighth in the table.
However, what they don't know is whether the club will get new owners on the day, and Pizzi said the club may not have a new commander at week's end.
"In what little experience I have of proceedings similar to this, I know that they always end up dragging out longer than expected, because there's always unforeseen problems that can crop up, or need clarification," Pizzi said.
"Whilst it's true that the deadline of Saturday is there, you can't rule out that it may be extended further."
Despite being assured of a top-10 finish in the Spanish top flight, Pizzi said the club has underachieved this season.
"We have plenty of things to improve, at a personal level and for the history of the club," Pizzi said.
"Valencia should finish much higher in La Liga than we have this season.
"We've been close to playing in a European final, but our aspirations should be greater, in accordance with what Valencia has always been in Spanish and European football."
Pizzi took over from Miroslav Djukic over the New Year period, taking charge of his first game at the club on January 4 against Levante.
The 45-year-old was not looking for excuses but said his men would be better for their experiences heading into the 2014-15 season.
"Rather than blame any shortcomings, the reality is that we arrived in a complicated situation, halfway through the season and in a difficult position, competing in three competitions and knowing that if we achieved the intended results, there'd be little time for recovery," Pizzi said.
"There would be hard work amidst high demands.
"In the Copa del Rey we fell by the wayside early on but in the Europa League we kept going for much of the season, which has been exhausting both mentally and physically.
"We've also suffered injuries in important positions. Amidst such a large number of injuries, we've lost three or four central defenders, so we've had to ask players to adapt. Throughout this maelstrom, we've been trying to get the best results we could.
"In La Liga, we haven't reached the heights we expected to, but in the Europa League, we were just one minute away from competing in the final. We've been self-critical of ourselves and we'll prepare ourselves well ahead of next season."
