Midfielder Luke Dobie made a 16-minute substitute appearance for Boro reserves on Wednesday afternoon, having been released by Everton earlier this season.
The 18-year-old will not be offered a contract at this stage, with Mowbray keen to have a first-hand look at a number of players as he begins to turn his attention towards the summer transfer window.
There will be a large number of domestic and European players becoming free agents, and the boss is compiling a list of potential targets.
"It (Dobie's trial) was done through the reserve-team coach and Academy people," said Mowbray. "I've had a look at him, but it's so far no more than that.
"If players fit the criteria, we will have a look at them. Everyone knows we will not be out there spending money on players, so if there are young lads who, like Dobie, are not going to get a contract at their clubs, we will have a look.
"There are lots of players across Europe who we will look at. There are agents all telling me about players who are not getting a deal for whatever reason.
"I don't take players in blind, I like to see them with my own eyes, rather than viewing an agent's footage, which will be just the best bits.
"There'll be a few players coming in between now and the end of the season, although we have to bear in mind where we will be next season in terms of finances."
With eight games to go, Mowbray is combining his long-term planning with his preparations for the final month of the season.
Middlesbrough's injury list has shrunk markedly recently, with Matthew Bates and Nicky Bailey both expected to be available for tomorrow's trip to Sheffield United.
Barry Robson is unlikely to face the Blades, although he has returned to full training following last weekend's lay-off with a hamstring injury, while Kevin Thomson will not be risked as he steps up his recovery from a leg problem.
Thomson has not been involved with the first team since New Year's Day, and it had been feared he would be forced to sit out the remainder of the season.
Those fears have been allayed, and having worked with the Scotland international during his time at Hibernian, Mowbray is looking forward to having him back.
While Bailey's combative qualities have been important in recent months, the prospect of a midfield alliance between Thomson and Rhys Williams is an enticing one.
"I really like Kevin as a footballer," said Mowbray. "He was a top player when I had him before, and he has matured and developed, with a very assured touch on the ball. He is a really high-quality player and if we can get him back, we'll have a greater chance of winning games.
"He's back on the training ground and looking good, but the acid test is getting him back on the pitch in a match where there's no hiding place in terms of going into tackles.
"In training, you can look after yourself, but in a game it's much more competitive. He's looked a quality footballer in training, but he's not had to deal with the crunching tackles you get in competitive matches. In the past, the first hard tackle has been a problem for him."
Source: Northern Echo
Source: Northern Echo