Steel Petrov is asking Celtic to win Brendan Rodgers and invest more to influence Europe.
Rodgers said on Friday he would add “new” to his squad in the summer to move the club forward.
“He was really smart by a strong coach who asked for a player,” said Petrov, who played for Celtic between 1999 and
“I think with the new European football format, Brendan feels more quality, more good players, he can do more in European football.
“We all remember that when Brendan came to the club, he talked about Europe’s adventures, which he wants to get more with Celtic in Europe, so he meant it.
Celtic reached the Champions League in February, losing 3-2 to Bayern Munich after winning three and winning three of their eight rounds.
Rodgers’ side are on the edge of the 13th Premier League crown in 14 years, and have already won the Scottish Cup semi-finals of the Scottish Cup in the Week semi-finals.
“I don’t think he’s worried at the domestic level, he has a strong team, he has good players, a healthy squad and he’s very happy with it,” Petrov said.
“But I think with his comments, he tried to challenge the board, and now the board needs to be answered. What you have to do is just go and spend money.
“I’m sure Celtic will do that because what I’ve seen in a year has been really good.