The moves benefit both the short and long terms.
Ekey, a 6-foot-7, 220-pound forward, averaged 6.5 points and 4.2 rebounds last season at Illinois State. A fifth-year transfer, he'll be eligible immediately.
Groce said Ekey's age and experience made him an attractive option, and his shooting (40.7 percent from 3 as a junior) would help ease the loss of perimeter-oriented seniors Brandon Paul, D.J. Richardson and Tyler Griffey.
Much like Sam McLaurin did last season, Groce expects Ekey to provide leadership.
"From a production standpoint and a leadership standpoint, we want Jon to be able to create some stability with the age and experience that he has, a little bit like Sam did for us this past year," Groce said.
As far as the way Ekey plays, Groce agreed that his game is comparable to Griffey's, albeit with a few twists. While Griffey had a bigger frame, according to Groce Ekey is more athletic and a better shot blocker.
"He brings that dimension like Tyler did as a pick and pop or skilled 4-man that stretches the defenses," Groce said. "That's the similarity between the two."
While Ekey will be of immediate help, Cosby is more of a long-term investment.
A 6-foot-3 guard that averaged 12.6 points and 3.0 assists for Seton Hall last year, Cosby will have two seasons left to play after sitting out next year.
Of the players Groce has coached in the past, it's Richardson that compared best to Cosby.
"I think D.J. is a great comparison from the standpoint of the intangible qualities that Aaron brings to the table, very similar to Richardson in that regard," Groce said. "I mean that with the upmost respect and compliment for D.J. because D.J. brought a lot of those things to the table that helps you win."
Cosby can play both guard positions and shot 47 percent from 3 in Seton Hall's final 15 games last season.
"He has very good range on his shot, he makes them both off the catch and off the dribble, so that's another dimension that he brings," Groce said. "But I think the comparison to D.J. is somewhat comparable for sure. I think Aaron might even potentially bring the team a little more versatility than what D.J. did."
Groce and his staff entered a deep market for transfers last month following the release of Mike Shaw, Devin Langford and Ibby Djimde. While the recruiting process in transfer situations can challenging due to an accelerated time frame, Groce and his staff had the same advantage with both Ekey and Cosby.
"The unique thing about these two guys is that we knew them," Groce said.
Groce recruited Cosby while at Ohio, hosting him for a visit and developing a strong relationship with his parents.
"I got a chance to get to know him (at Ohio)," Cosby said. "And once I decided to transfer, he started recruiting me hard again, so we have a little bit of a history."
The connections to Ekey were numerous.
Current Illinois assistant Paris Parham spent 2008-12 on staff at Illinois State.
And assistant Jamall Walker and Groce briefly recruited Ekey to Ohio before he decided to attend Illinois State because it was closer to his home of Independence, Mo. Groce coached against Ekey and the Redbirds on two occasions.
"I think you put all those things in a bundle and it made Jon comfortable with the opportunity at Illinois," Groce said.
With two needs sufficiently met, Groce said he could afford to be selective with the remaining scholarship.
Another guard to further ball handling and shooting skills is an ideal scenario, Groce said, adding that another forward to help with frontcourt depth could be an option, too.
"We treat these scholarships like gold, and we're going to make sure it's the right fit," he said. "If not, then obviously we feel comfortable pushing it to 2014 if need be."