Arsenal and Liverpool must keep hold of Alexis Sanchez and Philippe Coutinho if they are to make any impression on the Premier League title race, according to Jermaine Jenas.
Sanchez is unsettled at the Emirates Stadium and has been linked with a move to Paris St Germain and Manchester City, while the Reds have rejected a £90million bid from Barcelona for Coutinho.
Both clubs are fringe title challengers and former England midfielder Jenas believes that without players who act as the heartbeat of their teams, they will fade from contention.
"Sanchez and Coutinho fall into the same bracket for me - if you lose them, you might as well pack your bags and go home now. They're too important," BT Sport pundit Jenas said.
"I hope Arsenal stay strong and say 'we don't need your money, we need you here to get us back where we want to be and then you can go on a free'.
"I think Sanchez is worth that, even if you know you'd get £50million for him now and he'll leave next summer on a free.
"This has happened before to Arsenal - think of Robin van Persie and Cesc Fabregas. Do they want it to happen again?"
Manchester City have spent nearly £200million on new players this summer and Jenas believes they must be considered title favourites, although he insists it is the Champions League that boss Pep Guardiola really covets.
"I believe Man City will win it. Last year Pep had to get to know his team," former Newcastle and Tottenham midfielder Jenas said.
"He's faced something similar this season, but he's highlighted all the issues where he felt they weren't good enough and he's rooted them out. He's been ruthless.
"Looking at the players they have now, I can't see anything holding them back.
"The only issue might be that they have so much pressure on them to actually do it. You can't spend that much money and not expect to win the league.
"Spending money doesn't guarantee it, but Man City weren't that far away last season and right now they're the team to beat.
"For me Pep was brought in to win the Champions League because what's missing from the new Man City era is a European trophy so I think that's more the focus.
"If they didn't win the Premier League but reached the Champions League semi-finals, the owners will stick with him."