Press Association Sport understands the 22-year-old midfielder wants to hear what the Barclays Premier League outfit have to say after they tabled a bid of around £5million.
Johnson, who has scored 12 goals for the Coca-Cola Championship club this season, is out of contract at the end of the current campaign.
Strachan confirmed on Thursday that a series of potential buyers had contacted the Teessiders, some of them with verbal offers and at least one with a formal bid.
He said: "We have had verbal offers in the last week for Adam, but nothing has changed. Adam is still here and I would expect him still to be here for the last 19 games of the season.
"We have had verbal offers, we have had one official offer and I would imagine after looking at those that Adam will be here for the rest of the season, which we are quite delighted about because he is coming back into form."
Source: PA
Source: PA