Rangers secured the League One title with eight games remaining after Lee McCulloch's first-half hat-trick sealed a 3-0 win over Airdrie.
Manager Ally McCoist has challenged his players to continue their rise up the divisions, but the club's financial position remains fraught and he is unlikely to spend heavily in the summer.
Mohsni believes the Light Blues already have plenty of strength in depth and feels they can challenge for another title without any new recruits.
"I don't know if the manager will add some players, we will see," said the 26-year-old defender.
"Of course, the Championship will be tougher than this league, they have some good players.
"We played Falkirk in the cup and they were quite good. So I think it will be tougher but I am quite confident we can win that league too.
"I like this team. This team is fantastic. Look at the job we did.
"If he adds some players, if there are players who can help us it will be good, if he doesn't add players it will be good too.
"With the same team we can play in the Scottish Premier League.
"But I am not the manager."
The title triumph was greeted with jubilant scenes at Ibrox, but McCoist's men have come in for criticism this season, particularly after Sunday's 1-1 draw against Albion Rovers in the Scottish Cup quarter-final.
Mohsni remains confident his side will set the record straight in Monday's replay at New Douglas Park.
"They (Rovers) defended so deep, it was hard to find any space," he said.
"I was centre back but I was in the middle of the park.
"But they did very well, but they just had one chance and they scored. So well done to them. Now we have another game on Monday and I am quite confident."