'unable to rectify the problem' appears to be a somewhat contorted interpretation of what Ralph said at yesterday's press conference. He said that Salisu's (and others) injury situation has been hampered by being denied access to the injury recovery facilities at Staplewood. So, a player such as Salisu seems to find himself in a vicious circle whereby his lack of game time means he's unable to build up the appropriate muscle strength which results in recurring muscle strains which the club are unable to treat effectively due to the covid restrictions.
So, that said, I guess 'unable to rectify the problem' could be considered a valid interpretation of where Salisu is at the moment but one would hope that the situation will be rectifiable once the prohibitive covid restrictions have been lifted.
Yours thinking-out-loudly