Boro are awaiting test results to confirm the extent of the problem but if Strachan's worst fears are realised then the player he recruited to fire the club's play-off bid could be set for a spell on the sidelines.
The Teessiders haven't scored since Barry Robson's seventh minute strike set up victory over Peterborough United earlier this month but since then, in over 260 minutes of football, they've failed to find the back of the net.
McDonald has scored 14 times this season in a Celtic shirt but he's yet to open his Boro account and missed a penalty in the 2-0 defeat to Blackpool. Strachan believes the nagging hernia problem has prevented the striker from showcasing his predatory abilities.
Prior to his switch from Parkhead, McDonald flew to Germany for a hernia operation that was only expected to sideline him for a couple of weeks.
But he has been playing in pain for the last couple of weeks and Strachan is determined to get the problem cleared up rather than risk his prize asset suffering further.
Scott has a hernia problem and the operation he had has never really cleared it up, explained Strachan. He's not right that's for sure. He is away today to get it looked at to see if he can continue playing or he needs to rest it. But he is in discomfort.
We'll make a decision on him but it is a concern.
It's a shame because I don't think the Middlesbrough supporters have seen him at his best yet.
He has been playing with pain. That was his choice, he was determined to play.''
Since taking charge at the Riverside, Strachan has had to contend with a succession of injury problems and he's noted that the teams contesting the Championship's automatic promotion slots have all benefited from a settled line-up.
We need a consistent side because we've had a horrendous run of injuries,'' he said.
When I look at Newcastle I could pick the team give or take and it's the same with West Brom and Notts Forest.
We need to get to that consistency.
It would be great to pick the same side.
Killen is out, O'Neil is carrying an injury, Scott Macdonald is a doubt and everybody's had a touch of a flu virus that's swept through the squad.
Leroy Lita, Jeremie Aliadiere and Lee Miller will contest the striker positions tomorrow afternoon if Mc- Donald fails to be given a clean bill of health.
Strachan continues to be concerned with form in front of goal but has no complaints about the workrate.
We had chances to score goals and didn't take them. If they show the same commitment we got in the second half at Blackpool and the Forest game then I can sleep easy, he said.
We are short in midfield, we went to Ipswich and played with two full backs in midfield that's no fun for everybody. We are looking at players, not full-backs, who can maybe play in midfield for us.
Strachan refused to give any clues about potential changes on the flanks and was equally taciturn when asked to confirm if the club had a bid for Peterborough United winger George Boyd turned down.
I don't like to talk about other people's players,'' he insisted.
I don't care what (Peterborough director of football) Barry Fry has said.
Yes, we are looking to strengthen in midfield. We'll maybe do some business somewhere but what I've done in training is look at players in different positions so that might save us having to go into the loan market.
Cardiff's shareholders voted in favour of the sale of land at the club's state-of-theart stadium at an extraordinary general meeting.
The sale, to Bluebirds director Steve Borley, for the construction of a House of Sport will raise £450,000 and go a long way to plugging the £1.7million gap in taxes owed to Her Majesty's Revenue and Customs by March 10.
Chairman Peter Ridsdale, who also used the opportunity to field questions regarding the uncertain financial future of the Championship club, insists the deal will be completed in days and not weeks.
Source: Northern Echo
Source: Northern Echo