The former Leeds United striker suggested that the player should join Rafa Benitez at Everton.
The pair worked together on Tyneside during the Spaniard’s stint at St James’ Park.
Longstaff has seemingly fallen out of favour under Steve Bruce despite being linked with a big-money move to Manchester United two seasons ago.
“How often do we see it?" Whelan told Football Insider.
“Longstaff has obviously stayed in the mind of Rafa Benitez through the time he brought him through at Newcastle. Obviously an admirer, I very much think that’s the same for players towards managers as well.
“When you get these sort of relationships that have gone so well with players beforehand, you know you’re going to get the same commitment from them.
“It’s not a lot of money in this day and age for a young player. There’s still work in progress with him and he’ll understand that as well. You never stop learning as a player.
“There’s room to manoeuvre with Longstaff. I think he needs somewhere where it feels like he belongs, somewhere where he could get regular football.
“A club who’s going to put a bit more faith in him than maybe Newcastle have done over the past season. He needs a base, he needs some stability and I think that will probably bring out the best in him.”
We’ve gathered the best of today’s Premier League speculation below…
Longstaff has seemingly fallen out of favour under Steve Bruce despite being linked with a big-money move to Manchester United two seasons ago.
5. Foxes want McNeil
Leicester City are prioritising a summer swoop for Burnley starlet Dwight McNeil, with Brendan Rodgers keen on signing a left winger. (Fichajes) (Photo by Lewis Storey/Getty Images)
Photo: Lewis Storey
6. Swans eye Molumby
Swansea City could turn to Brighton's Jayson Molumby to replace skipper Matt Grimes if he leaves this summer. (The Sun) (Photo by Laszlo Szirtesi/Getty Images)
Photo: Laszlo Szirtesi
7. O'Brien stumbling block detailed
Leeds United may struggle to sign Lewis O’Brien because of a failure to agree a transfer fee with Huddersfield Town. (The Athletic) (Photo by George Wood/Getty Images)
Photo: George Wood
8. Toon favourites for Jones
Newcastle United are joint favourites to sign Manchester United defender Phil Jones, alongside Southampton. (SkyBet) (Photo by Alex Livesey/Getty Images)
Photo: Alex Livesey