Full-backs John Paintsil and Nicky Shorey, midfielder Lee Croft and winger Lee Cook all came on for the second half of Tuesday night's friendly at Brentford.
But the four players did not cover themselves in glory as, after a tight first half ended goalless, the Lions went on to lose 3-0 to their League One hosts.
Lomas is still looking to add to his squad as he attempts to keep the club clear of another relegation battle in his first season in charge.
"We're looking to bring in two or three permanents, but we'll have to see," he said. "We'll have to have a look at it, it's hard to say.
"We don't want to be in the same situation we were in at the tail end of last season."