Tony Pulis has revealed it will take "a few weeks" to get Jordan Hugill up to speed with the striker unlikely to feature before the international break.
Hugill arrived on a season-long loan deal from West Ham United earlier this week but he won't be involved in Saturday's Championship game against Birmingham City (KO 3pm) at The Riverside.
Hugill is making his way back from a hamstring injury and Pulis admits it will likely be after the first international break before he is seen in a Boro shirt, that takes place at the start of September.
The Middlesbrough-born 26-year-old, who spoke earlier this week about achieving a dream when he signed for Boro, will have to be patient for a little longer.
Pulis revealed: "Jordan's been injured, and hasn't had a full pre-season.
"It will take us a few weeks to get him properly fit and ready.
"I think it will be the international break before we'll see him."
There was better news on the fitness front for Jonny Howson, who was withdrawn in the second half of Tuesday's 3-0 victory over Sheffield United.
"Jonny got a kick rather than a strain or a pull so we're expecting him to be fit," added Pulis.
"I think out of the two games, he's been our outstanding player.
"I thought he was exceptional at Millwall when things weren't going so well and again on Tuesday night, his work in midfield getting forward and back."