Greg Smith and Ben Kitt have each signed two year contracts with Nottinghamshire.
Smith, who signed from Leicestershire ahead of the 2015 season, has passed 50 on three occasions in limited-overs cricket in 2016.
His unbeaten half-century guided the Outlaws to a six wicket victory at Edgbaston against the Birmingham Bears.
The 27-year-old also top-scored with 50 off 33 balls in the NatWest T20 Blast quarter-final victory over the Essex Eagles.
“Greg has developed his game, particularly in 20-over cricket, where he played some crucial innings and has made himself an important player for us moving forward,” said Nottinghamshire Director of Cricket Mick Newell.
“I talked a lot to our batsmen about, in the absence of James Taylor, needing to take that responsibility and show the toughness that’s needed to win games.
“The ability to be not out at the end is hugely important. Greg did that in T20 cricket and that’s a great sign.
“There’s no reason why he can’t expand his game to get more involved in red ball cricket and become a top four player across all formats.
“I’m very impressed with the way he has improved. Can he improve again in 2017? That’s the challenge.”
Academy graduate fast bowler, Kitt, has meanwhile been awarded his first professional contract having garnered 101 wickets in a combination of Second XI and Academy cricket this summer.
“We were looking at this year as a really important year for Ben and he has surpassed expectations,” said Newell.
“Over 100 wickets is a fantastic achievement for a young lad who has improved hugely.
“He’s very strong and fit, he’s bowled more overs this year than ever before, he’s got good pace, good aggression and a good bouncer.
“He can also bowl long spells and as he gets older he’ll continue to develop his skills.
“In a similar way to Jake Ball, he’s been here a while and is now kicking on, which is good to see.”