Carroll has been restricted to a handful of appearances for QPR since arriving on loan in September, but is due to return for Saturday's clash with Charlton after recovering from an ankle injury.
Jenas said: "Tom made the right decision coming here rather than playing Europa League games because the Championship is more competitive.
"He needs a lot more games at the top level to get that confidence. Hopefully his time here will have the same effect as it had for Andros."
Jenas added: "Tom went through a spell at Spurs where I don't think they knew what was going to happen. He was very slight, but he's worked very hard on his technique and fitness.
"He's one of the players I use to see after training constantly working on his technique, so to see him grow into the player he is is nice."
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