The Premier League world has been stunned this morning with the news that Chelsea have reportedly sacked boss Frank Lampard, with former Paris St. Germain manager Thomas Tuchel already lined up to take over.Frank Lampard’s time at Chelsea hasn’t lasted all that long, and while he’s had his ups and downs, it’s fair to say that he definitely did a lot of good for some players.While the likes of Fikayo Tomori, Kai Havertz, and Kepa Arrizabalaga struggled for traction under Lampard, plenty of other Chelsea stars thrived during his reign. In fact, some made an impact that may not have been possible without Lampard at the helm.Here are five Chelsea stars who improved under Frank Lampard.Chelsea Football Club has today parted company with Head Coach Frank Lampard.— Chelsea FC (@ChelseaFC) January 25, 2021#1 Mason MountMason Mount established himself as a key player during Lampard's reign at Chelsea.Probably the biggest success story of Frank Lampard’s time in charge of Chelsea is academy graduate Mason Mount.The young midfielder had already enjoyed a fruitful year playing under Lampard during his loan spell at Derby County. So when Chelsea’s record goalscorer took over at Stamford Bridge, it was clear that Mount would have a part to play.Nobody could really have seen how much of a key player Mount would become, though.Just 20 years old when Lampard took over Chelsea, he found himself handed his competitive debut for the club on the opening day of the 2019-20 campaign. And while that match didn’t go so well – a 4-0 loss to Manchester United – things quickly improved.Mount scored his first Chelsea goal a week later in a home game against Leicester and appeared in all but one of the Blues’ Premier League games, starting 32 of them. Along the way, he scored seven goals and registered five assists, and made his England senior debut in the process.The current Premier League campaign has seen plenty of changes in Chelsea’s starting XI, but Mount remained a constant under Lampard – starting 17 of the Blues’ 18 matches thus far.Capable of playing as both a creative midfielder, wide attacker, and a more combative #8, Mount’s versatility, tenacity, and hard work made him a favorite of Lampard’s and have also marked him out as one of Chelsea’s best players.Simply put, nobody else benefited from Lampard’s tenure as Chelsea boss quite so much.#2 Tammy AbrahamStriker Tammy Abraham became Chelsea's main source of goals under Lampard.It seems hard to believe now that he’s been fired, but when he initially took over as Chelsea boss in the summer of 2019, many people felt that Frank Lampard had a “free hit." That was because of the Blues’ transfer ban, preventing him from signing any new players in his first transfer window.Lampard instead turned to Chelsea’s much-vaunted academy, and one player who made the most of the opportunity given to him was definitely striker Tammy Abraham.Abraham was coming off an impressive season on loan at Aston Villa, where he’d scored 25 goals and spearheaded their promotion charge. But nobody really expected him to make an instant impact in the Premier League.However, the 23-year-old was trusted by Lampard to lead Chelsea’s line for the 2019-20 campaign, and in the end, the decision felt like a masterstroke.After reportedly working on his finishing with Lampard, Abraham first found the net for the Blues by scoring a brace against Norwich City. And from there, the goals simply flowed.By the end of the campaign, the academy graduate had scored 18 goals – 15 of them in the Premier League – and was the first English player to finish as Chelsea’s top scorer since Lampard himself.And while first-team opportunities have been more limited during the current campaign, Abraham’s 11 goals still mean that he’s currently the Blues’ leading goalscorer – and perhaps the best man to lead the line under new boss Thomas Tuchel.Leaving the Bridge with the match ball ⚽⚽⚽@tammyabraham pic.twitter.com/VEX7m2Rw8O— Chelsea FC (@ChelseaFC) January 24, 2021