Jon Shaw and Jake Howells scored the goals for the fifth-tier outfit at Kenilworth Road, but Lambert was pleased with the form of Belgian striker Christian Benteke, who last week U-turned on his transfer request and signed a new deal with the club.
Lambert said Tuesday's hit-out was an exercise in fitness for his players, but praised Benteke's 45-minute contribution.
"It was just another fitness thing tonight. Luton did really fine against us," Lambert told AVTV.
"The pleasing thing was Christian being back. Some of his touches were brilliant.
"He had 45 minutes. He's only done a bit of training. He's still got to work on match fitness but that 45 minutes will do him the world of good."
Lambert is, however, concerned by the number of quality players still on the sidelines at Villa Park.
"We have too many injures at the minute. That's the frustrating thing," Lambert said.
"When you look at the ones missing - the likes of (James) Okore, (Aleksandar) Tonev, (Gabriel) Agbonlahor, (Andreas) Weimann, (Nicklas) Helenius - there are a lot of big players absent.
"We want to get them back.
"Hopefully there might be one or two back for Friday. We will have to see how that progresses and see how it goes.
"Once we start to get everybody back, we will be pretty strong.
"But you're going to get injuries. That's the nature of the game."
Villa's next friendly will be against Crewe at Alexandra Stadium on Friday.
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