The former Manchester United player is holding out for a move back to Spain and he could sign for either Barcelona or Atletico Madrid.
United's disappointing campaign finished with a 2-0 home defeat to Cardiff on Sunday, with the club having missed out on qualification for next season's Champions League.
Some have blamed United's top brass, while others say Mourinho, dismissed in December, is responsible for the club's plight.
Manchester United, who finished five points behind fourth-placed Tottenham Hotspur, take part in their first friendly, against Perth Glory, on the 13th July. The whole group gelled together and I enjoyed winning but I know that football is hard.
"We started off fantastically".
"The boys were unbelievable when I came in". The Red Devils were flying high during his early days, but they have struggled to find their old mojo in recent months, securing just two wins in last 12 games.
"You can't just expect everything to go that way and the reality hit us". We are in a league with loads of very good teams and, to be at our top (level), we need to be 100 per cent focused.
"We have to take responsibility, all of us".
"They [coaches] are all going to stay".
Fellow Old Trafford loanee Axel Tuanzebe is hoping to join Henderson in the Premier League with play-off hopefuls Aston Villa and while Solskjaer seemed open to assessing the defender in pre-season, he was noticeably less committal when asked about Henderson's future by United's in-house station, MUTV. "I really believe in Michael (Carrick), Kieran (McKenna), Mick Phelan, in Demps (Mark Dempsey), but I think there is a tough job ahead", said Herrera.
"I am convinced it's not going to be because the right person is at the wheel", he said.
"I have to say it'll be nice for them to have a full season somewhere and play but then again maybe the best place is here, when you train with the best players in the world and in this environment".
The news follows last week's confirmation Mike Phelan would remain as the Norwegian's assistant after he signed a three-year deal.
Solskjaer admitted there will be no quick fixes as they attempt to bridge the chasm, though Herrera has faith in the former striker and his coaching staff.