Strachan said: "We are trying hard to bring in people who can lead and people who want to be led.
"I want to bring in leaders and men - that's hugely important now. I have to have people who I know, players I know who are men, who are leaders, and who know about playing at this level.
"There will not be any foreigners coming in this time, that's for sure. We have to add that wee bit of enthusiasm and knowledge."
Reports north of the border have suggested Caldwell, Robson and Flood were the main focus of discussions between the two clubs earlier this week as Boro attempt to re-shape their squad on a tight budget.
However, Strachan knows he may have to remain patient as he attempts to get his men.
He said: "Everyone plays games and wants to get the best deal they can for their club. It's brinkmanship - we will see how it goes."
Strachan, whose side have won just two of the 11 games for which he has been in charge, may be able to free up further cash by offloading players.
French midfielder Didier Digard is close to agreeing a loan move to Nice, while Egyptian midfielder Mohamed Shawky is in talks with an unspecified Turkish club.
Strachan said: "Didier is likely to go to Nice on loan for a while. That would free up some salary for deals to be done.
"He will be going on loan if a deal is done. I would think it's not far off."
Coca Cola Ch'ship Promotion 09/10 Win Outright: Middlesboro 6/1