The 32-year-old, who can operate as an attacking midfielder or as a winger, is out of contract at Leeds at the end of the season.
The Spaniard joined the Whites on loan from Al-Arabi in the summer of 2016 before making the move permanent in January 2017.
"Pablo's been one of the best performers for me when I've had him available, he's been one of the best performers," Heckingbottom told Leeds Live following Leeds’s 2-2 draw with Reading last weekend.
When asked if he believed Hernandez would be a loss, Heckingbottom said: ”Yeah, as I say when I've had him fit he's been one of the best performers for me.”
New contract a must
Heckingbottom has been in charge of the Leeds first team since the start of February 2018, but it seems that the former Barnsley boss has already realised just how good and important Hernandez is.
The former Swansea City and Valencia star is one of the best and most creative attacking midfielders in the Championship.
Leeds will be aiming to launch a challenge for the top six yet again next season, and Hernandez needs to be an important part of that.
Despite being 32 years of age, the Spaniard can play week in and week out, and his creativity and intelligence would only enhance the Whites’ chances of clinching a playoff spot next season.
It is time for Leeds to hand Hernandez a new contract and tie him down at Elland Road for the 2018-19 campaign.