Mason Mount believes Chelsea have raised their levels by signing Raheem Sterling.
The England forward has swapped Manchester City and Chelsea after the clubs agreed a £50m.
"Top, top guy. Obviously such an experienced player and a top-class professional," he told Sky Sports News.
"I have been lucky to play with him over the last couple of years with England, where he has captained the team at times.
"He is someone who has been there for a very long time. He is a top player and I have learnt a lot off him over the last couple of years.
"For him to be joining us is only going to bring our levels higher. He is definitely someone who strives for high levels and win. We want those players around this group and we want to keep striving for that. I am very excited to see him and for him to be here."