Top Cubs shortstop prospect Addison Russell is being called up to the majors, sources told CBSSports.com.

Russell will join top slugging prospect Kris Bryant, who was called up only Friday and is already making an impact with three RBI on Monday night against Pittsburgh.

Russell, who will be one of the youngest players in the majors at 21, will add to the stir on the North Side, where the talented young team has begun 7-5. Cubs manager Joe Maddon said the club is playing with "verve" after beating the Pirates on Monday.

Russell is batting .314 with one home run and seven RBI at Triple-A Iowa, and had a very nice spring training following his excellent 2014 season. He came to the Cubs from Oakland in the big July trade for Jeff Samardzija and Jason Hammel, who is back with the Cubs. Russell hit .295 with 13 home runs, mostly at Double-A last year.

Russell can play second base as well as shortstop, so second could be a spot for him in the short term. The Cubs have struggled at second, with Arismendy Alcantara batting .077 and Jonathan Herrera .192 so far. Tommy LaStella is on the disabled list, and another big prospect, Javier Baez, is in the minors. The Cubs have All-Star Starlin Castro at shortstop.

The Cubs very likely have baseball's best stockpile of positional prospects. Outfielder Jorge Soler is up with the big club and has been since late last year. Combine the players already up with Kyle Schwarber, Albert Almora and many others in the minors, and that  should guarantee the Cubs a superb everyday lineup in the near future, and quite possibly for years to come.

Touted Cubs prospect Addison Russell has been recalled from Triple-A Iowa. (USATSI)
Touted Cubs prospect Addison Russell has been called up from Triple-A Iowa. (USATSI)